Otakwen You are free to publish your story on other platforms if you choose to go with a non-exclusive contract, which Webnovel does. Each type of contract has its advantages and disadvantages, so it is up to you to decide which one is best for you.
You can search for a thread on this forum discussing the contract if you want more information about it. Alternatively, you can join the Webnovel discord and ask directly there. However, if you want more specific information, you should ask the Webnovel editor directly.