Some browsers default configurations can block login on Bkper with your Google Account. If you can't login, you can try some of the steps bellow.
Unblock third party cookies
Chrome:
1) Go to your chrome cookies settings at this url: chrome://settings/content/cookies
2) Check "Allow all cookies"
Other browsers:
Firefox | Internet Explorer | Safari
Logged in to different Google Accounts at the same time?
Logout from Google, by clicking in this link: https://mail.google.com/mail/logout?hl=en
Login again at: https://app.bkper.com/
Error 400: admin_policy_enforced?
Find Bkper and revoke access:
3. Go to https://app.bkper.com/ and login again
After authorization works, if you user any Add-on such Sheets or Forms, or Google Integration, you might need to reopen them and reauthorize too.