Signing on a iPad

Help. I’m trying to work out how to sign on a iPad. I need to sign a form on an email. Tried installing mark up but no wiser.
Am supposed to tap on toolbox icon but don’t have it( or can’t see it).
Any advice welcome.

Not tried it myself but this is what Apple say you should do,

How to sign a document on an iPhone or iPad

  1. Go to Mail, and open up the e-mail with the attached document .
  2. Tap the attachment to open it up.
  3. Tap the pen icon at the top right of the document .
  4. Next, tap the icon in the lower right corner. …
  5. This will open up a blank page. …
  6. You will now see your signature displayed over the document .

Not sure which email client you are using but I’ve tried it on my iPad and it only seems to work on an Apple iCloud account.

Thanks. For some reason the pen icon wasn’t coming up.
Apparently it’s the type of document I was sent. I popped into the Apple shop and there was one extra step for it and then your steps afterwards.
Thanks again.