Please ask someone knowledgeable to help answer this.

[darksam]

Does anyone know how to fix the code?

clif.cpp:25552:25: error: invalid use of ‘const_cast’ with type ‘int’, which is not a pointer, reference, nor a pointer-to-data-member type
25552 |         p->expireTime = const_cast<int>((st->expire_time - time(NULL)) * 1000); //if 0 == unlimited on client..
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
clif.cpp:25567:78: error: invalid initialization of non-const reference of type ‘item&’ from an rvalue of type ‘item*’
25567 |                         clif_add_random_options( p->items[slot].option_data, &st->items_inventory[i] );
      |                                                                              ^~~~~~~~~~~~~~~~~~~~~~~
clif.cpp:2794:93: note: in passing argument 2 of ‘void clif_add_random_options(ItemOptions*, item&)’
 2794 | static void clif_add_random_options( struct ItemOptions buf[MAX_ITEM_RDM_OPT], struct item& it ){

 

[alvisrynoc]

This looks like some custom code. i don't see the same code on rAthena master branch.

for the 1st error you can try removing const_cast<int>, for the 2nd error remove & from the line.
I cannot tell if my suggestion will work, because i don't have the full info. Provide more information i.e. the source code of the modified functions you added if you still need help.

but imo you'd get quicker result asking Chatgpt