At present Launchpad doesn't support incoming webhooks, but (as Inês said) it _does_ support code imports, which can be used to make a git repository on Launchpad that mirrors a repository hosted somewhere else. You can use that to do what you're asking for; the only downside is that code imports are updated a few times a day rather than immediately.
(As a bonus, you can use code imports in situations where you can't use webhooks, for example if you don't have permission to install a webhook on the remote repository.)
At present Launchpad doesn't support incoming webhooks, but (as Inês said) it _does_ support code imports, which can be used to make a git repository on Launchpad that mirrors a repository hosted somewhere else. You can use that to do what you're asking for; the only downside is that code imports are updated a few times a day rather than immediately.
(As a bonus, you can use code imports in situations where you can't use webhooks, for example if you don't have permission to install a webhook on the remote repository.)