The Davis Cup/BJK Cup requirements (two appearance, at least one in 2023/2024) still apply, but all players can apply through the exceptions...
1) Injury/Illness
2) Newcomer clause (their ranking was too low to be realistically selected until recently)
3) Strength of nation (their nation has too many top players)
4) Historic participation at Davis/BJK Cup and/or Olympics
The exceptions are pretty vague, but if you are a young player, an old player, from a nation with many players or just injury prone then you are probably safe.
Basically if you are in your mid-20s to low-30s and from a nation with few top players and in good health you better get your Davis/BJK Cup appearances in.