I think online for in-store pick up is your best option. If you don't have an appointment, you'll be waiting for a long time.
Just an FYI. Apple settled its lawsuit last month with Qualcomm for patent violation, and will start using Qualcomm chips again. They started using Intel chips in their XR, XS and XS Max phones, but Intel chips are inferior to Qualcomm chips. I would seriously consider buying something other than these phones.
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