Hello Ankit,
Thank you for reaching out. We currently do not have any endpoint to verify whether the accounts have permissions to manage the ads via API. It is only possible to verify this by logging into your Google Ads account. Please let us know if you have any concerns.
Regards,
Nikisha Patel, Google Ads API Team
Hello,
To verify if the client accounts are having sufficient access via UI, you could login to your manager account and navigate to the Tools & Settings > Account Access as mentioned in this article. The access levels for the user will give you the required details. Please reach out to our product support team via this link for more details as they are better equipped to address UI related concerns.
Regards,
Nikisha Patel, Google Ads API Team