Substitute for MathLink to integrate PARI with Mathematica?

How does one access MathLink with current version of Mathematica?

I’m trying to integrate the "computer algebra system" PARI with Mathematica, as documented at https://pari.math.u-bordeaux.fr/dochtml/mathlink.html . But command

when I try to establish the link inside Mathematica with

<< MathLink`

fails with a "Cannot open MathLink`", and

Install["./parishell",LinkMode->Launch]

fails with "Could not find MathLink executable."
(parishell is the PARI script shown in https://pari.math.u-bordeaux.fr/dochtml/mathlink.html)

How establish the linkage?