Note that not all sequences have to be linked to a specific company—you can leave the company field blank if you want the sequence to be shared across multiple companies. However, this approach may or may not be best practice, depending on your enterprise’s requirements
I now understand the issue. However, another problem has occurred — the companies are not displaying any data. I have already assigned the company in the Company module, but it does not appear in the Users section.
The reason “Current company” field is not displaying any data in the Users section is because first of all you need to add the companies into the “one2many” field “Companies” . Even if you have already created and assigned the company in the Company module, it will not appear in the Users form until you explicitly add it to the user’s list of companies in the o2m field.