Center 1: bring up a bar of three
Step 1 / 3
r: Right inner layer: turn 90°, front face goes up (Written as TR in the textbook)
The top is missing its whole left column. The front has a white bar of three in its right column.
r lifts the bar. U2 turns the left column to the right, r' sends the three wrong pieces down.
Step 1 of 3: r. Right inner layer: turn 90°, front face goes up