Whether you use an iPhone or an Android phone ... you can either select Done to save your changes or use the Share icon to send the amended document to another app like your email or cloud ...
To avoid that issue, you can use iCloud Drive on your iPhone to store your documents. You just have to know how to set it up and access it. What is iCloud Drive? iCloud Drive is basically the ...
Whether you use an iPhone or an Android phone ... If the above steps did accomplish what you need for your document, you can then tap Save in the top right to save those changes.