I AM GOIN TO TIJUANA NEXT WEEKEND.WILL I NEED A NOTARIZED DOCUMENT FROM THE OTHER PARENT?

HE IS IN TIJUANA WE ARE PLANNING ON GOING TO VISIT HIM BUT I'VE HEARD I WILL NEED THE LETTER...HE ISN'T FROM HERE SO HE CAN'T CROSS BACK TO GIVE IT TO ME AND THERE'S NO MONEY FOR HIM TO MAIL IT OR GET IT NOTARIZED.