Hmmm there are 2 ways:

1) fetch pair price of token from an API (i.e. Matic/USDT and dino/usdt).

2) fetch the reserves of each Liquidity Pool on a dex (i.e. quickswap). And then divide

Matic/usdt LP
Dino/usdt LP

2nd way is harder))

1st way it's easier but need to find an API