Adding custom labels or tags to a project task in Odoo can be a bit tricky if you're new to its interface. The problem you're running into is often a limitation in some views, but there’s a fix. So first, make sure you have the right access rights - you'll need to be a system admin or at least have the proper project permissions.

You should be able to add tags through the project app. In Odoo, head over to the project module, go to configuration, and then tags. Here, you can create new tags or labels. When youre in the Kanban view or form view of a project task, check if the tag field shows up. Sometimes it's not there by default, so you might need to enable developer mode.

Once you're in developer mode, inspect the task form view to make sure the tag field is visible and working. It can sometimes require a bit of customization in form view if the tag option isn’t shown. yeah, Odoo’s logic here can get a little weird. If the tags are missing, adding a custom field for them or adjusting the record rules might be necessary.

Remember, Odoo’s flexibility is useful, but tweaking it requires careful planning. Otherwise, you could end up missing up other parts of your system. So, go slowly!

If you want to add tags then bellow video will helpful

You should have the possibility to "create and edit" under "Needassistance", if not, you should maybe activate the developer mode and/or check your access rights. The other method to create tags is to go to "Projects/Configuration/Tags" (Odoo 9.0).