Not affiliated, but here’s the link to the pad, we got a size small. It may be just a centimeter or so too wide but worked perfectly: https://smile.amazon.com/gp/product/B08C9S198M/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
The Velcro straps are very secure and there’s a flap you can flip up to accommodate the backup camera
I got this one:
https://www.amazon.com/gp/product/B08C9S198M/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
It's actually kinda tricky to find a pad narrow enough for a Gen-1 tailgate. This one has been great though. It has thick, cupped padding where the downtube rests on the tailgate and the bikes don't budge on the interstate or tight turns. It's also been on the tailgate for about 4 months straight, rain or shine, and still looks and works great.
I will say though, it seems to only work well for modern bikes that have fatter oval tubing. I once hauled a 90's mountain bike with small round tubing and it didn't want to stay upright.
I ordered this one from Amazon and couldn't be happier: https://www.amazon.com/dp/B08C9S198M?psc=1&ref=ppx_yo2_dt_b_product_details
I read a lot of complaints about the velcro failing on the Yakima but I liked how it was designed. This mat has a similar padded 'cup' to hold the frame and protect it and it's also far cheaper. I've left it on the tailgate for almost a month now through rain and shine and the its holding up great. I don't use an ebike with it, but it holds my 29er MTB great.