Hello, Sadikul Islam,
In order to modify the word “From: “, you must change it in the Theme language files. You can use the Loco Translate plugin for this purpose. Please refer to the screenshots provided at the following links: https://postimg.cc/21g4sJ5f & https://postimg.cc/mtDCtRzs.
Additionally, please refer to our theme documentation for the Loco Translate plugin here: https://xstore.helpscoutdocs.com/article/30-base-theme-translation.
Best Regards,
8Theme’s Team