JavaScript:
<form name="form">
<!-- inputs and stuff -->
<input type="submit" onclick="javascript: form.action='/submit';">
<input type="submit" onclick="javascript: form.action='/submit-2';">
</form>
JavaScript:
<form action="/submit">
<input type="submit" value="Submit">
<input type="submit" value="Go Elsewhere" formaction="/elsewhere">
</form>
src - https://css-tricks.com/separate-form-submit-buttons-go-different-urls/
https://www.w3schools.com/Tags/att_button_formaction.asp