There is no restriction of selling mobile phone using Shopify Payments as long as this payment option is available in your country. Please try configuring the same in your payment section and let me know in case of any issue.
Hope it helps!
Unfortunately, I couldn't sell my phone on Shopify, maybe the problem was with the phone. However, a friend of mine recommend me a company that uses to buy already used phones, he said to me "there you could sell your Google Pixel". So, I contacted them and told about the phone I had and then I sent them the phone and after it, I received a hight payout for it. It was easier and quicker than I expected. I hope this information can help you somehow. Anyway, good luck to you.