1. Don’t share your OTP (One time Password) to anyone (either on call or email).
2. Don’t share your ATM/DC/CC pin number (Bank or an company didn’t ask for these things).
3. Always keep your password confidential and never share with anyone.
4. Beware of websites & social media pages that are propagating fake offers like person to person transfers to specific accounts.
5. Do not share your customer details, transaction IDs or order IDs over unsolicited calls.
6. Do not enter your Paytm account credentials any where except www.paytm.com
7. Change your password regularly.
8. Never share your card or bank details with anyone.
9. Create your password in alphanumeric way (using alphabets, numbers, special characters).
And Yes You can use security features to lock your paytm app so that nobody can use your app without your consent.
Always set up a screen lock/Pin/Password for your phone to avoid any misuse incase of theft or phone loss. Once enabled, you can secure your Paytm account with the App Lock Password. Find out how to enable it https://blog.paytm.com/now-add-an-app-password-to-your-paytm-wallet-81fa6118353c