How do I access my 2019 NJ tax return?

See https://ttlc.intuit.com/turbotax-support/en-us/help-article/prior-year-tax-return/access-prior-year-return/L7opE9vDA_US_en_US

Note that if you used a desktop product, the file would be stored on your computer and Intuit would not have a copy of your return.