The copyright notice is present in the footer on all desktop pages. On mobile, it is present on the homepage only.
Determines the text of the copyright notice to be displayed in the footer.
On the Admin sidebar, tap Content. Then under Design, choose Configuration.
In the grid, find the store view that you want to configure. Then in the Action column, click Edit.
Under Other Settings, expand the Footer section
Enter the copyright notice int he Copyright box.
When complete, tap Save Configuration.
On the Admin sidebar, go to System > Tools > Cache Management
Choose Flush Cache Storage.