Hello, Panicha,
Thank you for getting in touch with us.
Border radius from which block or element do you want to remove?
You can use screenshot tools such as Lightshot or Gyazo and share the links here. Alternatively, you can use a file-sharing service such as WeTransfer https://wetransfer.com/.
Thank you for your cooperation and we look forward to hearing from you soon.
Kind Regards,
8theme team