I do not have access to use Linear Mission under my Pro access.

I am seeing that your account has been downgraded to Free, likely due to multi-account abuse. Hit Sync and you will see that your access level is Free. You would need to be on the Pro tier to use the linear mission type.  

I tried deleting my account and signing up again 
and purchasing the Pro Service again, but it remains the same. 

But when I use Android, it works normally.

Could you help me, please
Thank you.

As noted previously, the account you are posting this from is on the Free level. That is why it says your Pro access is expired. 

You have blocked out the username and email address you are trying to use now so it is hard to tell what is going on. Please email us with the actual screenshots so we can try to figure out what is going on with your access. 

Judging by your flights I am going to guess you got this figured out. 

Sorry for the late reply. I have sent the video to your email. Please check it again.

Did you hit Sync in the settings as it tells you to?

Yes, I did as told.

Please try deleting the app and doing a fresh installation. There may be something going on with you having logged in with multiple accountsover time.

Your video does not show you hitting the Sync button shown here. This is what the screenshots above are telling you to do. 

We recommend starting from a fresh installation to clear out all of the other account's login information. 

Thank you for your valuable advice. I will be trying your suggestions in the next couple of days and will be sure to provide you with an update on the outcome. Sincerely,