How many backend languages is enough or too less? 1

So for context I am preparing for SDE roles. I have Node.js(with express.js) and Go on my profile. I recently applied for an intern role on linkedin where acc to its AI, my profile had several matches to their JD, with only python (Fast API) not being present. As obvious as it is, their went through my application and profile within 4 minutes of applying but no response(it was a 30k a month role so there would be a lot of candidates but still my profile got viewed this early and that the internship is definitely not a scam).

I have always heard that dont mention too many languages otherwise company would think u dont master any of them and blah blah.. u know. And that backend jobs arent language specific, they judge on skills.. so why I was rejected(technically) just because of not having fast api on my profile?

Also as said people mention having too many languages is a red flag. But there is a person in my college who is not in any coding clubs and not even known for coding, has java, C++, Python, Javascript and even R for her data science something interest.. so she did get an internship from a big company without any prior internship/open source/freelance. So doesnt she have too many languages too? She is also from a civil branch not some circuital.

Also one more question - is having only node.js(since go is irrelevant for freshers mostly) show in am not adaptable and unwilling to adapt to new tech stack for a company?

I'm a 4th chemical year student. So internship time is already over and I will have to look for full time roles without internships which is making me feel guilty..