Welcome to bike forums.

you are going to need to provide more details.

1. Brand, type and age of bike.
2. Does the click always occur when the crank is in the same position
3. Does the bike click if you stand up and pedal
4. Does it click in all the gears
5. Does it click on all chainrings
6. Does it click if you pedal with one leg (assumes clipped in)
7. Does it click with different shoes
8. Count the turns required to move the chain once around. Let’s assume 3.5
Do you have to turn the crank 3.5 times for every click
9. Does the click keep time with the rotation of the wheels

There, that’ll do for a start

Barry