The 403 forbidden error can occurs for 2 main reasons.
You are using the wrong gameforge email/password, and the bot fails to login.
Gameforge sometimes temporarily blocks IP addresses when the server automatically flag an IP as being suspicious.
In this scenario, you might get a 403 forbidden even with the right email/password.
You can either wait a few hours and retry once your IP is no longer blocked by the gameforge server.
Alternatively, you can fill the form to reset your password in ogame.
Once done you will be logged in on ogame's website.
You can then use your gameforge bearer token (from your browser cookies)
to create the bot, and provide the token in the "advanced" section.