Grid ASCII art code golf
Dyalog APL, 17 13 10 bytes

Prompts for an enclosed array containing (row, column) and then for a character. Gives INDEX ERROR on faulty input.
⊖⍞@⎕⊢5 5⍴0

Try it online!
⊖ flip upside-down the result of
⍞ inputted-character
@ replacing the content at position
⎕ evaluated-input (enclosed row, column)
⊢ of
5 5⍴ 5×5 array of
0 zeros