Why should I use PATCH instead of making a full update with PUT?
When you need to make updates, using PATCH makes things easier because you can make a partial update instead of sending the entire payload. Let's say you need to update the price for your listing. You can just send the price update with PATCH in the payload instead of sending a PUT call with an entire payload.
The access tokens you generate using the generateToken API are valid for 6 months. When they expire, you can use the refreshToken API to get a new access token. The refreshToken API requires a "refresh token" that was given to you in the original generateToken API call. If you don't have that refresh token, you should use the generateToken API to get a new access token.
Note: We recommend you use the refreshToken API to get new access tokens when they expire. You DO NOT need to generate a new access token before 6 months.