"Do i need to add all these parameter value or can i leave it blank."
∟ You could leave them all blank but then you will end up with a lot failed tests due to the lack of IP and ports to check. The script requires the inputs so it knows where to send the tests to either/or (a) management IP (b) virtual server IP:port.
∟ Generally speaking you could leave the filters blank, it will just attempt all the test HTTP requests instead of a subset of them.
∟ I'd recommend filling out the first 6 parameters.
"what should be the value for blocking regular expression pattern"
∟ If you use the default ASM blocking page then this can be left default.
∟ If you use a custom ASM blocking page where you modified the line "Your support ID is" then you may need to change the regex to match against your custom page. The regex is checking for a support ID returned from ASM to determine if the testing attack failed (received an ASM blocking page) or succeeded (did not receive and ASM blocking page)