If the standard browser update fails, some users report success by resetting the router and using the default IP in a fresh browser session to access the emergency upload page. ZTE ZXHN H108L with firmware 4.0.0d_ZRQ_GR4 ... - GitHub
Check the sticker on the underside of your router. Common defaults include admin or $LT@sltbb . 2. Download the Firmware File Web admin interface of the Hyperoptic ZTE ZXHN H298A Router zxhn h108l firmware