Mail form for downloading

Hello, and even if I’ve checked in the forum, I hope the question is new.
Il would like to know if there is a way to propose to a visitor to download a Pdf document at the condition he gives his mail address (the site is destined to sell services, and to help the site to be known I want to give some goodies and have a mail address in exchange). Generally, this is done with a window pop-up in other sites.
Ive tried to look at some scripts to embed, without any success.
Thank you!

You can give your gift externally via Gumroad.

Since you generally use email addresses to populate a mailing list, it’s generally done via mailing list features, like sending the link on the welcome email. Or like @macarna says, using a payment button and sending the PDF via some form of automation (zapier, ifttt, etc).

Thank you. I didn’t know this service. Could be interesting for a lot of things.

Thank you Duncan. Yes, you are right, a mail php form could do it, with a thanx page containing the link. I have to consider if it could work for me as, if I have several goodies to give, I should have the same amount of mail address to get the right number of thanx pages with link.