These entries are queried from radb.net using whois, you can try my project getting these.
:AS139832 route: 103.146.2.0/23 origin: AS139832 descr: Sylhet-Net Broadband mnt-by: MAINT-SYLHETNET-BD last-modified: 2020-01-05T12:05:43Z country: BD mnt-routes: MAINT-SYLHETNET-BD mnt-lower: MAINT-SYLHETNET-BD source: APNIC rpki-ov-state: valid route: 103.146.2.0/24 origin: AS139832 descr: Sylhet-Net Broadband mnt-by: MAINT-SYLHETNET-BD last-modified: 2020-01-05T12:05:26Z country: BD mnt-routes: MAINT-SYLHETNET-BD mnt-lower: MAINT-SYLHETNET-BD source: APNIC rpki-ov-state: valid route: 103.146.3.0/24 origin: AS139832 descr: Sylhet-Net Broadband mnt-by: MAINT-SYLHETNET-BD last-modified: 2020-01-05T12:05:09Z country: BD mnt-routes: MAINT-SYLHETNET-BD mnt-lower: MAINT-SYLHETNET-BD source: APNIC rpki-ov-state: valid