The [first] lead can be reported as suit + rank, or rank + suit.
You can skip the rank (i.e. just enter the suit) if you do not remember exactly which card that was lead.
The “skip” button can be used if you have forgotten the suit as well.
HOW TO CORRECT MISTAKES
Mistakes should be corrected as soon as you spot them and at the very latest before the end of the round.
BridgeTabs offer several convenient methods to change incorrect entries, see a separate page for details.
Note that you need to click on the declarer button if you have to amend an incorrectly reported lead.