`show route where bgp_export() all` output states that 2602:feda:ab4::/48 prefix is unreachable. That most probably reason to not export it. As it is static route it's probably point to some interface in DOWN state, or unreachable gateway.

Yakov Sh.
telegram: @darkyman

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, August 17th, 2021 at 1:30 PM, 智慧雨泽 <zhihuiyuze@gmail.com> wrote:
Hi, bird user
       It seems that the image attachment cannot be seen by others, so I resend it (
       I want to export 2602:feda:ab4::/48. I wrote 「if bgp_export() then accept」 in the BGP template, but it was not exported to BGP correctly. But bgp_export() outputs 2602:feda:ab4::/48.
      I can't find the BGP in the bird document under what circumstances will not export prefix, please tell me, thanks!
       
bird> show route export Hurricane_Electric_LLC
Table master6:
2a10:cc44:100::/44   unicast [UNM_Exch_RS2 2021-08-13 from 2602:ffb1:200:0:192:34:27:253] * (100) [AS38281i]
       via 2602:ffb1:200:0:192:34:27:6 on ens19
2a10:cc44:109::/48   unicast [LL_IX 15:22:24.526] * (100) [AS38281i]
       via 2602:feda:ab2:5247:5247:5247:5247:5247 on ll_ix
2001:df6:9f80::/48   unicast [EVIX_RS1 2021-08-13 from 2602:fed2:fff:ffff::1] * (100) [AS38281i]
       via 2602:fed2:fff:ffff::107 on ens20
2602:feda:ab2::/48   unicast [LL_IX 2021-08-15] * (100) [AS141011i]
       via 2602:feda:ab2:5247:5247:5247:5247:5247 on ll_ix
bird>


bird> show route where  bgp_export() all
Table master6:
2602:feda:ab2::/48   unicast [LL_IX 2021-08-15] * (100) [AS141011i]
       via 2602:feda:ab2:5247:5247:5247:5247:5247 on ll_ix
       Type: BGP univ
       BGP.origin: IGP
       BGP.as_path: 141011
       BGP.next_hop: 2602:feda:ab2:5247:5247:5247:5247:5247 fe80::200:5efe:5bd:ff6b
       BGP.local_pref: 100
2602:feda:ab4::/48   unreachable [BGP_Prefix 2021-08-13] (200)
       Type: static univ
bird>


template bgp tpl_bgp {
graceful restart on;
local as LOCAL_ASN;
ipv6 {
next hop self;
import filter peer_in_v6;
#export where bgp_export();
export filter{
#if my_opt_prefix() then bgp_path.prepend(LOCAL_ASN);
if bgp_export() then accept;
if bgp_export_downstream() then accept;
else reject;
};
};
}