The most important parameter is
sonar.pullrequest.branch is only useful if the ALM (Bitbucket) integration is not working, otherwise the branch name is automatically retrieved from the PR key (or id).
I can see from your last post that now the PR analysis integration is working fine. You indeed have the expected SonarQube check on the right column of the PR
To see a bit more of the decoration, you need to click on this SonarQube check to have more details.
In the current case the check mark is green meaning that the PR passes the quality gate and, as confirmed by your SonarQube screenshot, that there is no issues in the code. So there will be nothing more in the Bitbucket decoration.
It is only in the case where you have some issues in the PR that you will see a bit more decoration, highlight in bitbucket where you have those issues, like in the below screenshot:
To have issues in the PR obviously you must have added new code in thr PR (ie in the source branch of the PR). I wonder if that is something you did? Did you not simply create a branch and a PR without any new code in the branch ? In that case the PR decoration will not very spectacular since there is no new code, no issues and no real metrics on new code.