How do I switch to an Instagram Business Account?
- Go to your profile and select Settings.

- Go to Account.

- Tap Switch to Professional Account. NOTE: If you are "Switch account type" instead of Switch to Professional Account, this means your Instagram page is already set to a professional account.

- Tap SWITCH when asked "Switch to a business account?"

- You will be asked several Onboarding Questions like this; just click on CONTINUE.

- Select a Category for your business and tap Done.

- You may be asked if you are a CREATOR or BUSINESS. Select one, then tap on NEXT.

- Setup your professional account or tap X on the corner to return to your profile.

For further reading, see Facebook's help article: Set Up a Business Account on Instagram