The CARES Act mandated a 2019 NOL be carried back unless an election to waive was made.  If election to waive was made, then NOL went to 2020.  If it wasn't fully used in 2020, then it is coming forward to 2021 on line 14a from the 2020 column.  There isn't a 2019 column because there is nothing from 2019 going to 2021.  2019 has to go to 2020 first and now becomes part of the 2020 carryforward to 2021.

QBI losses have to come forward.  If a QBI loss originating in 2019 wasn't used up in 2020, the remaining amount becomes part of the 2020 column amount being carried to 2021.  Again, no need for a 2019 column.

Both NOL and QBI losses carry forward indefinitely.