How long should /does it take to get a promotion or a rase?
I am working for 1.5 years and currently on minimum wage still.

Usually not before you and your boss have that talk and you both agree you're worth more to the company then minimum wage...

@C0D4 best answer. Also look at the average pay price od your position and so some job search just to have a feel of the market and what ypu are worth.

Stand up for what you are worth. Waiting is useless unless you know where you could go.

At least a year in my opinion, but more is reasonable. Unless you provide a lot of value; then it can be quicker, depending on the company/bosses.

You should definitely have some kind of review by this point which generally comes with a raise of some kind (never enough). You'll likely need to feel out the market and/or get an offer before management will do anything significant.

A developer should never make minimum wage because it's not a minimum skill or intellect job.

I worked in hospitality for 5 years and left because it took so long to get a promotion, "considered" for 3 years. In my first tech job, I was promoted after 5 months.