- Log in to Admin Panel.
- On the Admin Panel sidebar, go to Stores > Settings > Configuration.

- In the left panel, choose CUSTOMERS > Customer Configuration.

- Expand the Name and Address Options section.

- Untick Use system value and set Show Company to “Optional” or “Required”.

- Click Save Config when complete.
You can see the company field displayed in the Address Book.

And display on Checkout Form.
