Apple Watch Series 6 not charging with red lightning bolt

My Apple Watch Series 6 will not charge the only thing that the face of the watch will show occasionally is a red lightning bolt and the time of the day. I have tried the reforce trick, but it did not work. can you help?

[Re-Titled by Moderator]

Original Title: My Apple Watch six series will not charge the only thing on the face of the watch occasionally is a red lightning bolt and the time. How can I fix this issue?