Can't see "Start timer" button in Jira (own domain) with Chrome plugin

I watched the video and followed the instructions on this page:

I changed these settings in my Clockify plugin:
Integrations > Custom domains.
I put in my custom domain (service.mydomain.com) and enabled it for Atlassian and Custom Atlassian.

We use Jira v7.12.3
We don’t use cards, our issues are opened in the sidebar or in an seperate browser tab.

Hi Mateng and welcome to our forum!

We appreciate you reporting this, however, please note that Clockify forum is dedicated to new feature suggestions, improvements, and general product feedback, but not bug reporting.

All bug reports and such issues should be sent to support@clockify.me where our support team will be able to help out and take note of the problems.

Thank you for understanding!