Is it fine to use the same mkcert certificate for both your frontend and backend?

I’m developing a webapp that uses vite on the frontend for my local testing environment and also a separate API backend.

I used mkcert to generate a local dev certificate and am using that one for the backend.

My question is, for my frontend dev environment I also can use a certificate, as shown here in the vite config:

server: {
  https: {
    key: fs.readFileSync('key.pem'),
    cert: fs.readFileSync('cert.pem'),
  },
  proxy: {
    '/v1': {
      target: 'https://127.0.0.1:8080'
    }
  }
}

My question is: can I use this same generated certificate (key.pem and cert.pem) for my backend and frontend servers? It seems to work okay, but I’m not sure of the implications for this.

I generated my mkcert certificate using the following command:

mkcert localhost 127.0.0.1 ::1 192.168.1.96