Getting Lincoln an adaptive bike

**PLEASE SEE UPDATE** THANK YOU ALL SO VERY MUCH! This is Lincoln, he is 6 years old. As some of you know when Lincoln was 1 he suffered a TBI from an accidental gun shot. He is in a wheelchair and works hard everyday to gain his strength and abilities back but that is very challenging as you could imagine and sometimes for him pretty boring lol. There are so many wonderful things I wish I could get for him to use but unfortunately insurance doesn't pay for everything and I am a single parent of 3 kiddos so money is alway tight. Lincoln got to try riding a bike for his first time and he absolutely loved it and it would be so good and amazing for him to have his own to help build his muscles and enjoy himself. This is something that would be great for him all year as he can use it at school during PE since he's unable to do most physical things. The bike he needs is not like a regular bike other kids use and sadly costs usually 5x as much. So I am asking if you are able to donate any amount I would greatly appreciate it and it would make a very special boy very happy! I am asking $500- $1200 to cover the bike & shipping cost a helmet and straps for lefty and gofundme fees. My mom found this one on ebay that is almost exact to the one he tested I'm hopeing we can get it. https://www.ebay.com/c/1522855192 Unfortunately it is local pick up from Michigan but I sent them a message to hopefully arrange shipping if we pay! Cross your fingers! I have checked out a few other bikes but sadly they are more costly so please feel free to help any way you can. If you find anything online suitable for him or know anyone selling one please get ahold of me on fb. The major things it needs is abductor separater and seatbelt and back support and strap as shown. I would appreciate any links to other for sale or any leads.
Please share even if you can't donate and thank you all so very much!