Claiming is the mirror image of the pointing pair. This time you scan a row or column: if every place a digit can still occupy on that line falls inside a single 3×3 box, then the line has claimed the digit for those cells. The box must give up the digit everywhere else — its other two mini-rows lose the candidate.
Row 7 confines digit 3 to the bottom-right box (blue) — the rest of that box loses its 3s (red).
Scan row 7 for digit 3. Placements in other columns block every cell except r7c7 and r7c8 — both inside the bottom-right box. Row 7 has claimed the 3 for that box's middle band, so the box must surrender its other 3 candidates: the marks at r8c8 and r9c9 go.
Do not mix up the direction of the eliminations: claiming clears the BOX (outside the shared cells), pointing clears the LINE. Erasing along the row here would be wrong — the row is the side making the claim.