Fedora 33 docs aren’t published yet. I’ll refer you to the Rawhide install docs, as they’ve been minimally updated for Fedora 33. (I’ve got a PR to update install docs with Fedora 33 screenshots, which hopefully will land soon.)
See Manual Partitioning Figure 16 shows a drop-down menu partitioning scheme preset. It’s LVM in this screenshot but will be Btrfs in Fedora 33. If you click the blue link above to automatically create partitions, you’ll get the same layout as the Automatic partitioning selection on the earlier screen (Figure 12).
That automatic scheme looks like Figure 21 in Manual Partitioning: Btrfs
Click on either
/home. On the far right you’ll see a section named Volume and a Modify button under it. Click that. This is how you configure the entire Btrfs volume. Reduce the size by the amount you want for a swap partition. Change the name of the volume (optional). And also check the Encrypt box (optional). Click Save to exit this area.
Now you can click
+ on the lower left side UI, and add a swap “mountpoint”. If you leave desired capacity blank, it uses all remaining free space. You can also click the Encrypt checkbox on the right-side UI.