Using Priority pragma in commit message has limitations and in some situations PRs do not end up running with higher priority.
A more reliable method is to use Build with Parameters in Jenkins.
PRs need to be approved to run with priority. Please talk to your manager if there is a need to use this for your PR.
Step #1: Go to Jenkins for your PR. You can do this from link in github.
Step #2: Click on the PR-XXXX menu and this will take you to the classic Jenkins view
Step #3: Remember to login to Jenkins on the top right.
Step #4: Once logged in, you will see Build with Parameters option on the left panel.
Step #5: In Build with Parameters page, fill in 2 for BuildPriority and TestTag accordingly if it applies to your PR.
TestTag field is the same as Test-tag pragma in a commit message. If you are not planning to use Test-tag in commit to target specific or additional tests, leave this field blank. Else, fill in with what you plan to tag as you would in the commit message.
Step #7: Click on Build at the bottom of the page. You should see a new build kicked off and the previous build aborted.