Walmart-backed OnePay offers credit and debit cards, high-yield savings accounts, buy now, pay later loans and a digital wallet with peer-to-peer payments.OnePay, the fintech firm majority owned by Walmart, is launching its own branded wireless plan as it seeks to become a one-stop shop for its users, CNBC has learned.OnePay Wireless will be available starting Wednesday in the OnePay app, according to Gigs, the mobile services startup that partnered with the company.The plan costs $35 a month for unlimited ...