Sweetmielo Theme demo content insatall showing Request failed. Error code 426

When trying demo content install in sweetmielo theme getting Request failed.Error code 426. How to install demo content successfully? It is urgent. Anybody please help?
Screenshot 2021-12-17 095920

That’s a strange error and it will be hard to debug without knowing how the theme works etc.

Best option is to contact the author from the item’s support page here:

any possibility you know about this error?

Please contact the author of the theme to get support: