Previous postdoc supervisor removed my name in the published article

You're putting the cart before the horse here. Step 0 is to contact your previous supervisor and ask for clarifications. You may or may not get an answer, and if you get one it may very well disappoint you, but I'm willing to bet no journal editor or university administrator will want to proceed unless you first tried to resolve the issue with your old supervisor.

If the situation is as you describe, then indeed there is a case for a correction to the paper (or at least some editorial action). Although you have left your previous institution, they would not be enchanted to hear that one of their employee is accused of this form of plagiarism, so if you have a case they are stakeholders in this story.

You might want to be quite careful when giving percentages as you did in your OP. The published paper might differ only in some small but crucial aspect from the rejected one even if the texts show significant overlap, and one can easily imagine that this is what your old supervisor will use in defending his position. Also from a strictly semantic perspective, your supervisor did not "remove your name from a published article": he did not properly include your name as co-author when he resubmitted a rejected manuscript to a new journal. That's not quite the same, although of course the outcome is the same: you're not a co-author.

This is why contacting your former supervisor to clearly understand the rationale behind his actions is essential. The last thing you want is for you to loose this case as it could impact your reputation at your new institution and with journal editors.

It could be that your co-author attempted to reach out to you in order to get your permission to use your name but never got a response, i.e. old email/ not known address, ran out of time and had to publish without your name.

I would advise getting in touch with your colleague first in order to establish what happened before using the nuclear option. It may be your colleague will assist in amending the published article.

Wow, yes that is completely unethical. I recently stopped working at an academic institution, but I still collaborate with my former colleagues and we continue to publish old projects that I was involved in, with me being an author still.

I think you have two options:

1. Contacting the university you did you postdoc at. Email the head of faculty, or if necessary higher up, and explain what this person has done. It may prompt them to retract the paper and take disciplinary measures against him, which would hopefully stop him repeat offending.
2. Contact the journal, as you suggested. When someone publishes a article, they usually have to agree to an authorship contribution statement. If he has claimed 100% authorship, this is a pretty serious offence, and any journal worth their salt would take an accusation of false misrepresentation seriously. The hard part for you might be proving your contribution. Do you still have the copy that was rejected from the previous attempt to publish, and the rejection email? This would be valuable evidence.

Good luck with you endeavour.

Yes, you can complain to the editor. If you complain to IEEE, the publisher, they will probably refer you to the editor.

You can request retraction or request a correction adding your name as an author. A correction would require the agreement of all authors.

You can also complain to the university, but the university can only punish the supervisor. They cannot cause the journal to do anything.

These are options. They are not necessarily useful options.