What line number of the following code contains an error and what type of error is it$?$

$1.$ def sales$\_$tax$($amt$)$:

$2.$ print$("$Welcome to the $6\%$ tax calculator!

$")$

$3.$ sale $=$ amt $+($sale $*\mathrm{.}06)$

$4.$ return amt

$5.$

$6.$ print$("$The total amount after tax is: $",$ sales$\_$tax$(95))$