use cell value in this formula

[LeighH20]

Can anyone show me the correct way to use the value of cell E20 in this formula? My attempt returns an error.

Many thanks.

[#2]

@LeighH20 

Perhaps

=XLOOKUP(1, INDIRECT("'"&$A$1&"'!I3:I"&$E$20), INDIRECT("'"&$A$1&"'!E3:E"&$E$20), "-", 0, 1)