What expenses? Are you talking about open access fees or something else? Generally one does not incur any expenses in the publication process unless you actively opt for open access during the publication process. I don't know how things work where you're at, but in my experience generally expenses are covered by some grant or another, or possibly by departmental funds.

Does "expenses" refer to publication fees? If yes, are there reputable jounals in your field that don't charge the authors any fees? "Since my supervisor doesn't have any contribution in it, I cannot request him to cover the expenses for this paper." Why not?

Is there any reason you'd be afraid to ask your supervisor other than the money? Do you have a good relationship? Will they support independent work or punish you for it?

What "should be" and what "actually is" are different things in different places to different people.

@Buffy, Is there any reason you'd be afraid to ask your supervisor other than the money? Do you have a good relationship? Will they support independent work or punish you for it? --- For some reason, my supervisor seems to be lying a lot to me. As a result, I don't trust him anymore.

@JonCuster, If yes, are there reputable jounals in your field that don't charge the authors any fees? --- I might be mistaken, but as fasr as I know open access journals requires fee payments. Since my supervisor doesn't have any contribution in it, I cannot request him to cover the expenses for this paper." Why not? --- He has been lying a lot in the past few months. So, he lost my trust.

@AdamPřenosil, What expenses? Are you talking about open access fees or something else? --- as far as I know Open Access journals ask for fees.

If you don't have funds to pay for open access publication, why would you choose an open access journal?

Your advisor lying to you is a quite different problem.

@BryanKrause, If you don't have funds to pay for open access publication, why would you choose an open access journal? --- I really don't know. Everyone around me are publishing in open access journals. So, I thought, I should do the same.

@Buffy, Your advisor lying to you is a quite different problem. --- I have a feeling that he is giving his native students more opportunities to work on different projects. So, if I tell him that I want to publish something, he will probably undermine me. I am not in Western Europe where society is immigrant-heavy.

"Everyone around me are publishing in open access journals" Well, then ask them what procedure they go through when they need to ask for funds for open access. No-one here can tell you what the precise procedure is at an unknown university in an unknown part of the world.

Can you send the article to a subscription journal and bypass the issue entirely?

@Allure, Open access is my preference. Coz, it is just easy to show my work. I have written to the editors of a journal about the possibility of a fee waiver. I am waiting for their response.

@user366312 just easy to show my work I don't understand this, it should be just as easy in a subscription journal, especially if you can upload a preprint somewhere.

@Allure, OK. I will check on that.