The "Hidden Pairs" solving method has the same principle as the "Hidden Singles" method. The only difference is the number of cells and notes. If you find that two cells within a row, column, or 3x3 block contain a pair of candidates that do not appear anywhere else in that house, then those two numbers must be placed in those two cells. All other candidates can be removed from those two cells.
For example:
Let's look at this block with its notes and search for numbers that appear less frequently as candidates. Only two cells contain the candidates 2 and 6. This means that 2 must occupy one of these cells, and 6 must occupy the other.
No other numbers can be placed in these two cells.
After reaching this conclusion, you can remove the extra candidates from the notes in these two cells to avoid confusion.
Now you know how to apply the "Hidden Pair" method in Sudoku. It's time to get some practice!