fetchError: unable to verify the self-signed certificate along with net::ERR_CERT_AUTHORITY_INVALID with put method

Question

I am using a next js node server as my app. And a ngnix as my https server with self-signed certificate in which my API node server is at behind.

But I am getting a self-signed certificate error.

So, in my next js , I will contact the https server either by fetch and axios. for example.

Is there a easy way on how to get ride of it without buying SSL from real CA?

What I have tried:

This problem couldn't be by pass thru chrome insecure content enabling since it is a server error.

I am guessing this could be achieved from either setting node server / fetch or axios. But I am so new on this kind of problem.

second update

process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0; 

works to get rid of the fetch error:

But now it shown this error with put method:

net::ERR_CERT_AUTHORITY_INVALID

What I have done is to put process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0; on every api call.

For example

   try {
      process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0;
      const res = await axios.put(url);
     
    } catch (error) {
      console.log(error);
    }

I am still looking for a solution.