hide share btn when its not users creation

src/components/MainHeader.jsx

@@ -84,6 +84,8 @@ export function MainHeader({
 								</span>
 							</Button>
 						)}
+
+						{!isNotMine && (
 							<button
 								class="btn btn--dark hint--bottom-left"
 								aria-label={i18n._(t`Share this creation publicly`)}
@@ -103,6 +105,7 @@ export function MainHeader({
 								</svg>
 								{currentItem.isPublic ? null : <Trans>Share</Trans>}
 							</button>
+						)}
 
 						<button
 							class="btn btn--dark hint--bottom-left"