There are several ways to add the block:
Via the block inserter
Via the shortcut slash (/) command
By typing in photoblock
and pressing enter.
Click on the (+) icon in the block editor to insert the block. Search for photo
and you should be able to click on the block.
When in an empty paragraph block, you can type /
and have several shortcuts showup.
Search for /photo
and you should see the block.
In an empty paragraph block, type in photoblock
and press enter. The Photo Block will be added for you.