Conditional action on buttons

As Bernd says, you'll need to write a script for this type of task. However, it's not as simple as you might hope.

Here is an of articles that will point you in the right direction:

https://acrobatusers.com/tutorials/submitting-data

https://acrobatusers.com/tutorials/conditional-execution

If you need help with scripting you'll find tutorials here.

pdfscripting.com

Now the reason it's not so simple is that the "doc.submitForm" function doesn't indicate directly if the submit was successful.  It returns a true/false value, but it will return true even if the URL doesn't exist. This is because this function is Asynchronous. It returns before the submit is complete. The true/false value just means it started the submit. To truly detect a successful submit you need to receive a status value from the server on the return. A hidden field could be used for this. And you'll need to modify the server script to return a PDF data format. What is the server returning now?

A very simple solution might be to use two buttons, one for each action. Then you don't have to muck about with all this.

Use Javascript code for this. Check the required fields. When all required fields are filled submit the form and clear the form.