What device type are you trying to flash, Lina? How much flash do you have? What version are you trying to upload? How big is it? What model router? What version IOS? You haven't provided enough background for anyone to help you adequately.
The guide that @pieterh pointed out is a good place for information about setting up HA and the caveats to understand.
The calculation for the number of nodes is not so simple. You really need to calculate the number of total ports. For instance, t...
Do you have a monitoring profile configured? Is it applied to those devices? Are the devices configured to accumulate the stats? For the basics the devices probably don't need a configuration but for other metrics you might.
You're getting a 403 on that URL for some reason. I would suggest you open a service request with TAC to investigate further. They might need the nbi logs to debug why that URL is troublesome. If you're able to GET from other URLs, even within the sa...
I'm not aware of a v3 for the webacs API. There's a v1 and a v2, though. The v2 interface handles JSON arrays consistently no matter the entity counts.
Can you show any of the headers that your client is sending and any of the raw response, please?...
