A tax return being accepted is only the first step in the process. It must be completely processed and approved by the IRS before they will send a refund. It will be sent in the way you directed it to be sent when you completed your tax return. You can't change it from the way you indicated on your return when it was filed.
What does the IRS tracking web site say about the status of your refund:
https://www.irs.gov/refunds
Here is an IRS Q&A with information about refunds:
https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions
See this for additional info about current IRS status:
https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue
