How to rename Tags in ADO? from lowercase to camelCase

I have many tags in my tickets on ADO, most of them are qa, manual, search page etc... I want to introduce a new system for tagging them, and instead of qa I want "QA", instead of manual I want Manual, instead of search page I want SearchPage, but when I try to rename them, because for example "qa" already exists, when I tag it as "QA", it goes to lowercase automatically, is there a way for me to change this?

As suggested in the documentation "Add tags for work items", you can use the extension "Tags Manager" to manage (delete and rename) tags.

After installing this extension into your Azure DevOps organization/collection, open a project, under Boards section, you can see the Tags option. Click on this option to open the "Tags Management" page.

On the "Tags Management" page, you can see the tags which have been added before (e.g., qa, manual, search page, etc..). You can rename or delete the existing tags.

For your case, you can rename the existing tags from qa, manual and search page to QA, Manual and SearchPage on the "Tags Management" page. To rename a tag, you need to click on it and enter the new name, then press Enter key to save it.

After renaming the tags, reopen/refresh the work items which had been added the old tags, you can see the old tags have been automatically changed to the new tags.

And when you try to add tags to a work item, you also can see the new tags are listed as available.