Mpokket legal notice

I have taken loan from mpokket app of 10k. They are harassing me with phone calls and I don't know what to do. The made interest of 10k against my loan. Because of lockdown I couldn't repay my amount. From the time of lockdown, I don't even have money to run my daily needs. They sent me a legal notice saying that I should repay the amount of 20k. I am mentally and financially disturbed, I don't even have the money to repay back the amount. So please help me with the details how can I overcome this harassment. I don't know what to do I am very disturbed mentally.