How do I reactivate my apple account?

From a post by Apple Community Specialist Brittany1416 in thread Inactive Apple ID - Apple Community :

"We'd like to get you some help with this issue. For this issue [an inactive Apple ID], please contact Apple Support for assistance. You may be able to reach Apple Support here: Contact - Official Apple Support "

Telephone numbers --> Contact Apple for support and service - Apple Support

Note that having an "inactive" account is not the same as having a disabled account. If you mean it is disabled:

● If the message says "your account has been disabled in the App Store and iTunes Store" or "locked" then you must contact Apple; you cannot resolve this yourself. Apple provides a link for this specific issue. Tap or click here --> https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362 .

● If your account has been disabled for security reasons the solution is to reset your password as outlined in this document: If you forgot your Apple ID password - Apple Support

If you are unsuccessful you may need to request account recovery as outlined in this document How to use account recovery when you can’t reset your Apple ID password - Apple Support , or additional assistance from Apple Security: Contact Apple for help with Apple ID account security - Apple Support

If it's another reason then post here with details.

Get more help and assistant from Apple directly, see Contact Apple for support and service -> Contact Apple for support and service – Apple Support (UK)