These entries are queried from radb.net using whois, you can try my project getting these.
:AS6456 route: 208.90.168.0/22 descr: ALTOPIA-V4-1 assigned by ARIN origin: AS6456 notify: hostmaster [at] alt.net mnt-by: MNT-ALTOPI-1 changed: hostmaster [at] alt.net 20180925 source: ARIN rpki-ov-state: valid route: 208.90.168.0/23 descr: Spectrum Networks LLC customer route origin: AS6456 mnt-by: MAINT-AS11404 changed: john [at] vanoppen.com 20080801 #20:55:57Z source: RADB last-modified: 2023-11-13T15:51:16Z rpki-ov-state: valid route: 208.90.168.0/23 descr: ALTOPIA-V4-1 assigned by ARIN origin: AS6456 notify: hostmaster [at] alt.net mnt-by: MNT-ALTOPI-1 changed: hostmaster [at] alt.net 20180925 source: ARIN rpki-ov-state: valid route: 208.90.170.0/24 descr: Spectrum Networks LLC customer route origin: AS6456 mnt-by: MAINT-AS11404 changed: john [at] vanoppen.com 20080801 #20:56:24Z source: RADB last-modified: 2023-11-13T15:51:16Z rpki-ov-state: valid route: 208.90.170.0/24 descr: ALTOPIA-V4-1 assigned by ARIN origin: AS6456 notify: hostmaster [at] alt.net mnt-by: MNT-ALTOPI-1 changed: hostmaster [at] alt.net 20180925 source: ARIN rpki-ov-state: valid route: 208.90.171.0/24 descr: ALTOPIA-V4-1 assigned by ARIN origin: AS6456 notify: hostmaster [at] alt.net mnt-by: MNT-ALTOPI-1 changed: hostmaster [at] alt.net 20180925 source: ARIN rpki-ov-state: valid route: 208.90.171.0/24 descr: Spectrum Networks LLC customer route origin: AS6456 mnt-by: MAINT-AS11404 changed: john [at] vanoppen.com 20080801 #20:57:34Z source: RADB last-modified: 2023-11-13T15:51:16Z rpki-ov-state: valid route6: 2620:0:cf0::/48 descr: Spectrum Networks v6 proxy registration for alt.net origin: AS6456 mnt-by: MAINT-AS11404 changed: john [at] vanoppen.com 20100310 #00:46:05Z source: RADB last-modified: 2023-11-13T15:51:16Z rpki-ov-state: valid route6: 2620:0:cf0::/48 descr: ALTOPIA-V6-1 assigned by ARIN origin: AS6456 notify: hostmaster [at] alt.net mnt-by: MNT-ALTOPI-1 changed: hostmaster [at] alt.net 20180925 source: ARIN rpki-ov-state: valid