In the last 40 years I've spent mostly in the USA I rarely have heard Uruguayan/Argentinian Spanish in person or in media, but was surprised to hear Messi and others in recent interviews use SH as in "puSH" for the Y/LL, this apparent has been a generational shift in that area, first in Argentina and then Uruguay. I'd sound old-fashioned if I were to go back to Montevideo these days.
"ll" in standard spanish is a strong english "y".
However, in spanish argentinian from the area of Buenos Aires (but not the argentinian Córdoba, which sounds more like colombian spanish) it is "sh", being that s something like a mix in-between of "j" and "s" + h as in "she" but the sound is a bit different.
Without being able to record some sound I cannot express it better but I am sure you can find something around. Javier Milei, the president, has such an accent.