Request to external server is possible in MV3?

Question

I found MV3 didn't allow to inject external scripts. Then does Google allow to send request to my server from MV3? Please tell me any other way if you know.

Example,

window.fetch(
  'https://my-server/update',
  {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    credentials: 'include',
    mode: 'cors'
  }
)

I'm using the example code in MV2.