The challenge you face is finding a trustless way to move from LTC or MATIC into BTC without exposing yourself to surveillance or identity checks. The most important thing in your position is to minimize risk both in terms of custody and counterparty trust. Wherever possible avoid leaving coins on any platform even for a short period. Peer to peer exchanges that operate without KYC such as Bisq or AgoraDesk can be useful but they require learning how to use them securely. Another option is looking into decentralized swap protocols that let you trade directly from wallet to wallet for example atomic swaps or certain scriptless swap tools which do not require accounts.

If you can learn these tools you gain two things. First you avoid reliance on centralized exchanges that will freeze accounts. Second you keep custody over your coins during the swap. This takes more effort than simply clicking through on an exchange but for someone in your environment that extra learning curve is worth it.

The key is to treat every transaction as a potential threat vector and think about privacy in layers. Protect your IP address. Protect your keys. Protect information linking your identity to your activity. Bitcoin should be a shield not another way for the authorities or middlemen to track you. The more you understand and control the process the safer you are.