.Formula not working. I bet this is simple!

I am having an error with the code below to insert a formula into Range A4:A(whatever last row is). Anyquick fixes? My formula is:

Formula:

=IF(B3="","",TEXT(RIGHT(INDIRECT(ADDRESS("MATCH("Date: "&"*",$M:$M,0),13,4,1)),LEN(INDIRECT(ADDRESS(MATCH("Date: "&"*",$M:$M,0),13,4,1)))-6),"mm/dd/yyyy"))

Sub FillFormulas()

Dim Lastrow As Long
Application.ScreenUpdating = False
Lastrow = Range("M" & Rows.Count).End(xlUp).Row
Range("A3:A" & Lastrow).Formula = "=IF(B3="","",TEXT(RIGHT(INDIRECT(ADDRESS("MATCH("Date: "&"*",$M:$M,0),13,4,1)),LEN(INDIRECT(ADDRESS(MATCH("Date: "&"*",$M:$M,0),13,4,1)))-6),"mm/dd/yyyy"))"

End Sub