Got it working, finally! Thanks for all the help!
Here is the final code below. The first button edits the current record, redirects to another record in another table and edits that record, and then brings the user back to the current record they were on.
How can I mark this as solved or answered?
var text approve = URLRoot() & "db/" & [_DBID_] & "?a=API_EditRecord&apptoken=xxxxxx&rid=" & URLEncode ([Record ID#])
& "&_fid_12=" & URLEncode("Approved")
& "&_fid_13=" & URLEncode(Now())
& "&_fid_14=" & URLEncode(User())
& "&rdr=" & URLEncode(URLRoot() & "db/xxxxx?a=API_EditRecord&apptoken=xxxxxx&rid=" & URLEncode ([Related Store Item])
& "&_fid_14=" & URLEncode([# of Features Requested]))
& URLEncode("&rdr=" & URLEncode(URLRoot() & "db/xxxxx?a=dr&rid=" & ([Record ID#])));
var text reject = URLRoot() & "db/" & [_DBID_] & "?a=API_EditRecord&apptoken=xxxxx&rid=" & URLEncode ([Record ID#])
& "&_fid_12=" & URLEncode("Rejected")
& "&_fid_13=" & URLEncode(Now())
& "&_fid_14=" & URLEncode(User())
& "&rdr=" & URLEncode(URLRoot() & "db/xxxxx?a=dr&rid=" & ([Record ID#]));
