how to use the features in premium subscription

[#1]

Help pls!

this is for iOS -phone and iPad

i just purchased the premium subscription 

but when I open adobe reader and load a pdf file, I don't seem to find any additional feature brought by the newly purchased subscription 

my goal is to edit an exiting pdf, change some txts and delete some signatures, etc

thanks!

[#2]

Read this:

https://www.adobe.com/devnet-docs/acrobat/ios/en/editpdf.html