What is the proper meaning of 随便? 由于版权原因，Up主不能随便阅读别人的小说进行视频创作。

I looked up 随便, and there are 3 possible meanings,

casual


random


informal

Which one do you think fits?
随便 can 'do as one wishes'

'freely' would be a suitable translation in this context
不能随便阅读别人的小说 - cannot freely read other people's novels