Adobe not showing as option in outlook

[#1]

For some reason on my iPhone 6 when I try and open PDFs from outlook Adobe doesn't come up as an option.

When end I click on the share button Adobe isn't there.

How is do I get it so Adobe is an option again as it has been in the past?

Thanks.

[#2]

Duplicate post by the same user.

Please see Can't open PDF in Adobe from Outlook

Thank you.