The code name “gprimeltexx” is used for the Samsung Galaxy Grand Prime (SM-G530FZ) “gprimeltexx” and isn’t referred to as “Galaxy S4 GT-I9505”.
TeamWin - TWRP lists the Samsung device “gprimeltexx” and offers twrp-3.1.1-1-gprimeltexx.img.tar for the Galaxy Grand Prime (SM-G530FZ) .
[CUSTOM BUILD] Unofficial Pie Build for Galaxy S4 - GT-I9505 (jfltexx) is available for download here.