Okay. GitLab employee here. The next few things are my personal experience at GitLab. They don’t reflect anything official from the company or the experience of everyone there.
You should ensure that you have a career progression plan with your manager. It can be something like a career matrix. You should talk to your manager about: Where am I skilset wise, what do I need to do to progress into the next „tier“ of my current seniority, what do I need to do to jump into the next level of Seniority. All these definitions may be different depending in your company.
You should ensure that you work on your goals and talk to your manager regularly about them. Make sure to keep a journal or brag document to reference things that you have achieved. Make sure that you document your plans and your progression. You should be the one demanding this process from your manager, it is your career, not theirs. Remind them to do this with you.
If your higher management doesn’t have documentation and processes that define how one progresses in the Org, demand it. You can only progress in the org if you know how to. This also allows you to see if your personal goals don’t align with the Org, that it might be time to move away from that org.
Finally a personal note that I had to learn: Be straightforward about what you want. Supply your manager with the stuff that they need. In my case I changed managers quite a bit due to the growing org and it never felt like the right time to ask for a promotion from Interim to Official Manager.
If you are doing the job in a satisfactory manner already, ask for that promotion. If you are showing seniority, ask for the promotion. Make sure to have the data to back it up. If told „no“, ensure you get the specific reasons why not and work on resolving those issues.