Issues with using #seats shortcode

We have been using Events made easy for our online registration for years. It has always worked well and did what we needed. This year we switched forms of payment and I was able to update everything after I copied the old registration form to use the new payment method. (switched from Paypal to Stripe).
I wanted to change the way we accepted donations on the registration form and add selection to add a donation to the form so that it would add into the total. We are using #_SEATS in the shortcodes for other registration selections and thought I could just add another “Seat” shortcode. Everything I have done has created an error message. I have copy and pasted changing the seat number and wording, I have typed it in making sure I follow the code style and still an error code. What am I missing? Or is there a different code I can use to create a field to select or insert a donation amount to add to the registration total so the attendee can pay for them both in one transaction.
Thank you for your help.