We have to not use refresh token, and we have to not store tokens at browser side. isn't it?

What type of application is it? An SPA (Single Page Application, such as Angular, Vue, React) or a Regular Web App with a backend?

Please see my direct reply here (in case it is an SPA):

which is about a similar question.

In a SPA, you don’t use a refresh token. Also for the access token, you should only hold it in memory, not store it in local storage. That applies to SPAs. See:

I wonder why many jwt posts recommend the refresh / access token policy.

It’s for regular web applications with backends, not SPAs.