The send is a workflow, not a message
Most people treat a digital invitation as a text they type fresh each time: the address here, a corrected time there, a separate message to explain parking. By the tenth send you are retyping the same details and the replies live in six different threads. That is the backwards way to do it.
The correct order is the opposite. First the page exists, holding every detail in one place. Then the send is trivial: paste the link, add two lines that make it sound like you wrote it for that person, done. Everything changeable lives on the page, so the message you send never needs correcting later.
The final piece is the reply. A good digital invitation collects answers against names as they arrive, so the send is also the start of your headcount. You are not sending a nice note and then beginning the work; the note and the counting are one motion.