To attach this to your iPhone Apple Mail:

Open this page on your iPhone in a browser. Chrome or Safari will do.

Tap on the signature to select and hold, then drag the selection handles to the bottom of the signature and top to select the entire email signature.

Tap Copy.

Close out of your browser and go to settings.

Scroll down to Mail.

Scroll down to Signature.

Select per Account.

Tap inside the field of the email account you wish to install your signature into.

Tap again and hold, then select Paste.

Now, the formatting might not be perfect, and that’s okay; shake your device and select undo. This will correct any weird formatting.

You can now close your settings, open your mail app and compose a new email. You should see that your email signature is automatically inserting and looks great.