Paste your Tonkeeper wallet address (it starts with UQ or EQ). It's public: it lets the app look at your balance and history, and nobody can spend with it. Never type your 24 secret words anywhere.
Your data syncs between your phone and laptop through your private Cloudflare account. A backup file is extra safety: save one now and then and send it to yourself on Telegram. Your GRAM balance and history always come back from the wallet.