There is an error.
There is a problem with the logo.
www.dog.walk.adalo.com
but,
adalo → share → previewer(SHARE APP->COPY LINK)
This link doesn’t have a problem with the logo. However, subdomains have problems with logos.
If you delete the bookmark, then re-add it and wait a few seconds before tapping Add to Home Screen it will fully pull in the logo for you.