The push(@INC...) happens when your script is running, but the use kp1 happens at compile time, when @INC is not yet set. Two ways to fix it:

# make sure not to use a variable that is only set at run time
BEGIN { push (@INC, "/home/usr/scripts"); }
use kp1;
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or

use lib "/home/usr/scripts";
use kp1;
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