We want to add an API, from one of our providers, they give us a client id and a secret key, this must be done in a POST call, it delivers the Token for the api, I would like to know how or where I can do it to generate it and add it to the API connection
You can use Custom Actions to make calls to External APIs: Custom Actions - Adalo Resources.
The exact implementation depends on your provider’s API. It may be sufficient to use a custom action to send request for a token and then store it in some Logged-in User property (and then use this token as an authentication).
In other cases it might be better to use 3rd party tools like Make to create an integration with external API (e.g. if clientID and secretKey needs to be combined in some complex way).
Also you may explore the way of creating the custom component for your API, but this will require coding experience.
Best regards, Victor.