Hi Vi,
Thank you for contacting support. I understand that you are looking for developer token. Please note that developer token is associated with production manager account. To confirm whether you account is a production manager account you can check below:
For a Test account you will be having red label with Test on top right corner, if you don't see that label your account is a production account.
By clicking on the question mark on the top right corner of the account you can confirm if it is a manager account. It should specify "Your manager account customer ID: XX-XXX-XXXX".
To have the API center option, you must have production manager account. You could create a new manager account from here. If you still have concerns, please share the account id of your manager account, I will confirm. Please use reply privately to the author option while sharing the information requested.
Regards,
Nikisha Patel, Google Ads API Team