Follow below mentioned steps to get your SoundCloud User ID:
Step 1 : Go to SoundCloud
Step 2 : If you have an account with SoundCloud, Sign In, else Create an account
Step 3 : Click on the See More icon present on the top right corner
Step 4 : Click on Settings
Step 5 : Click on the Content tab
Step 6 : Here, you will see your User ID, Copy it
Step 7 : Now Paste the Copied User ID in the SoundCloud ID field