Do imports affect foreign exchange reserves?

Yes they do, I believe it's also the main reason why a lot of things get stuck at customs and stay there for months. I worked in customs 5 years but I left it, I now do forex trading and buy and sell cryptos. Check https://www.dailyforexjournal.com/ if you too are interested in the topic of forex trading and markets.

of course it doese, higher imports higher demand for foreign currency which leads to local currency depreciation.

sure it does in a way because when importing individuals sells the local currency and buys foreign currency (USD,EUR...etc) as a result banks do the same through interbank or central bank (FX position maintenance) ,if the difference between exports and imports (current account) is in minus this means the country is losing FX reserves.