The 2021 tax return must be attached to the W-7 form and mailed to the W-7 submission address ...
If you are filing your tax return as Married Filing Jointly you must apply for an ITIN with the tax return and you would need to be providing a statement with your tax return that you want your Nonresident Alien Spouse Treated as a Resident. See IRS Publication 54 Tax Guide for U.S. Citizens and Resident Aliens Abroad pages 6 and 7 - https://www.irs.gov/pub/irs-pdf/p54.pdf
Go to this IRS website for ITIN information - https://www.irs.gov/individuals/international-taxpayers/general-itin-information
