Open Bank Sandbox - Cloud Firebase index errors

[serviceintegrat]

Please, if someone knows how to solve this:

In the installation of the Open Bank framework, with Cloud Firebase, a database model is generated.

Access to collections returns errors with the non-generation of indexes.

Sample:

{"gqlQuery":{"allowLiterals":true,"queryString":"SELECT * FROM users where username= \"user123\""}} 

Execution response:

{"error":{"code":400,"message":"no matching index found.","status":"FAILED_PRECONDITION"}} 

All WHERE generated by the framework against the database fails because of the same type of error.

I appreciate any help. Thank you!