Blockchain – How do I know the price of a currency on a DEX?

I received a list of decentralized exchanges:

Uniswap V3(Ethereum), Jupiter, Uniswap V3(Arbitrum One), Quickswap(v3), Ramses V2, Pancakeswap V3(Linea), tanX, Meshswap…

How do I get currency prices from these exchanges programmatically?

I realized that I could use the API or SDK provided by the DEX or interact directly with the smart contract. But since I’m new to this issue, I’d like to hear an expert’s explanation.