How to renew Nepal visa when it expires?

As long as you have a way to leave the country, China's border guards won't stop you (China wouldn't let you leave the country if your visa expired before). You can apply for a visa on arrival at the airport. Just line up and do it with foreigners for a few minutes. Kathmandu Immigration Bureau is near the Embassy of China. Take a taxi and say immigration. Drivers know that. A few minutes' drive. You can find this phone number on the website of the Nepalese Pavilion of the Embassy of China. But to go in person, two 2-inch photos are ready. Just fill out the form and queue up to apply. The visa fee is very cheap, tens of RMB. The first time is free. If you can't leave the country, you can only apply for an extension in advance at the Nepalese Embassy in Sanlitun, Beijing or the consulates in Shanghai and Lhasa. You can ask someone to do it for you, and it will arrive in a week by express delivery.