I need to remove charset=utf-8, from Content-Type. I have to use fetch, and for now I'm sending this:

fetch(`address/${endpoint}`, {
      method: 'PUT',
      headers: {
        'Content-Type': 'application/json'
      },
      body: JSON.stringify(testData)
    });

this is how it looks like:

I have to remove a charset. If I didn't clarify it enough, please tell me.