Hi guys, does please know if/how can you show an image on a background that is randomly selected from the collection? I was thinking of using random picker but it seems like it shows only text and if I use an image, it is not a random one. Thanks 
It is not clear if you want to show a random image on screen visit or upon pressing a button.
Here is my hack (not elegant but works 
)
I set up a collection of images. " field in the collection. Image and Name. For name, I entered a number from 1 to 10.
Blank screen:
I placed a random picker on the screen that picks a number between 1 and 10. I also put an input field (you can later make this field to be invisible under styles, also 1 by 1 pixel, etc). Once random picker picked a number > update input field with the number.
I placed an image on the screen. I made the image to be a list of images. Max item 1. I also adjusted the list height to show 1 image only. Filter: Image name equals input value.
voilá
If you want to make the same if someone clicks a button you could do the following:
Everything same as above except you can remove the random picker and replace it:
On button click > update input value > custom formula > Rand(1,10) where 1 represents the minimum and 10 the max.
Update:
If you want to display a random image on button click this option is better:
Place an image and make it a list. Max items: 1
Place an input field
Place a random picker
Image list filter: Name contains input value (it is important to select contains. I tried with equals and it didnt work)
Random picker set up:
Collection : Images (or whatever. Basically the same collection as the image list above)
What happens when user clicks on component?
Pick a new item
Action after refresh:
Update input: Value: Current item’s name.
Hey, thanks for your response! My bad, I want the image to be shows on a background without clicking on anything, make it automatic.
In this case the first idea should give you some inspiration with the random picker + input combo. Are those static images or uploaded by users?
Those images are the ones uploaded by users
Ok here is another solution:
You would need to upload the first image to the database and give it a 6 digit number for example: 100000
Now, when a user uploads an image, you can add a unique ID to the image with the following formula:
Images>Id>Maximum+1
This will create 100001, 100002 and so on for every image as it takes the last images maximum Id and add 1 which becomes the current image’s ID.
Next step:
Add a randomizer component to the screen which generates a number between:
Images>Id>Minimum and Images>Id>Maximum
Once the number is generated you can do an action: update an input field (which you also add to the same screen. Please note you can make the input field invisible by setting the opacity to 0 etc.)
Now you can add an image to the screen and make it a list of images > Max to display:1, ID equals input’s value. Another filter: ID does not equal 100000 (because this was your first image that you uploaded)
Every time a user visits the screen a new number is generated. However if you dont have much images, the component can not guarantee that the same number will not be generated more than 1 time)
Let me know if something is not clear and I’ll try to explain it better.
PS: If you expect a lot of images, you can amend the number of digits up to 10 or whatever)
Thanks a lot for your advice! It sounds a bit difficult but I will give it a though and let you know 
Just let me please ask you, I am planning to use that to generate the background for the opening screen, do you think it will work there? And maybe a stupid question but why does the number need to be 6 digits?
It can be any digit. Depends on how many images you will have.
Question: How many images you expect? Are they unique for each user? Are you showing them after log in?
I was planning an unlimited number as users would be able to post them by themselves. Yes, they are unique as each image can be added only by 1 user. Yes, they are shown after log in too
I made an example for you. Cloneable link:
https://previewer.adalo.com/068e5538-3dd1-46ae-85c0-210b0310ea60
Every time you login / preview the app a new random image is showing up from the user collection
Of course you can hide the input field, it is just for demonstration purposes. I usually make if 1px by 1px with opacity of 0 for all settings. I used an input field because it is faster then writing the database. This trick can also be used for some limited custom states
Thank you very much! Really appreciate that 