While there isn't an endpoint, maybe one quick way to test it out is to send a request to get a particular contact via email: Get a contact by email address? If it returns with the contact details, the hapikey is right. If it returns hapikey (xx) doesn't exist, the hapikey is wrong.
While there isn't an endpoint to check if a HubSpot API key is correct/active, you can access your portal API key under Settings > Integrations > API Key and click show.
Is exist any endpoint to test if apikey is correct?
SOLVE
I want to be sure that the key provided by the customer is correct and active so I would like to make a test connection with HubSpot for verification. Of course, I can do it on any endpoint but I thought maybe there is one empty that will return only 200
While there isn't an endpoint, maybe one quick way to test it out is to send a request to get a particular contact via email: Get a contact by email address? If it returns with the contact details, the hapikey is right. If it returns hapikey (xx) doesn't exist, the hapikey is wrong.