How to create your own keyboard shortcuts on the iPhone
Start the Settings app.
Tap "General" and then tap "Keyboard."
Tap "Text Replacement."
Tap "+" in the upper right corner.
Type the text phrase you want to create, and then enter the text shortcut that will trigger it when you're typing. So in this case your Personal Document link would be the phrase, and something like “smd” which stands for Send Me Documents (or another shortcut of your liking) would be the trigger/shortcut.
Tap "Save."
Set Up Custom Text Shortcuts on the Samsung Keyboard
Most Samsung devices have the Samsung Keyboard as their default keyboard (unless you have manually changed it).
To add custom text shortcuts to your Samsung Keyboard, you first need to head into your phone settings.
From here, scroll down until you see General management. Here, you’ll find the settings for your Samsung keyboard.
Select Samsung Keyboard settings and then select More typing options.
Open up Text shortcuts and select the + button in the top right-hand corner to create a new shortcut.
Enter the word or phrase you would like to use as your shortcut (ex. smd), and then enter the full text you would like it to expand to (this is where you’d place your Personal Document Link).