Mod: Xaero's Minimap
Link: https://www.curseforge.com/minecraft/mc-mods/xaeros-minimap
Description:
Xaero's Minimap is yet another minimap mod with terrain mapping and waypoints, but it also has many additional nice features, such as entity radar, cave mode, multi-world detection, etc. However, unlike most popular minimap mods, this one doesn't come with a full-screen world map, so for full functionality, it is recommended to also install Xaero's World Map from the same mod developer (xaero96).
There is also a "non-cheaty" edition of this mod called Xaero's Minimap (Fair-play Edition), which doesn't have the features that are often considered very unfair (e.g. entity radar and cave mode).
VERY IMPORTANT NOTE:
Xaero's Minimap is a mod that works on BOTH sides — client-side and server-side as well. Naturally, when the mod is installed on the client side only, it has limited functionality, but still works very good. People may not know about the server-side functionality, as it is a relatively new thing that was introduced in version 20.20.0 (source: https://chocolateminecraft.com/update.php?mod_id=0), quote:
Quote2020/08/07 Update 20.20.0 (MC 1.16.1, 1.15.2, 1.14.4, 1.12.2, 1.8.9, 1.7.10):
[...]
+ Added the first server side feature. Installing this mod on the server side (in addition to client) will now make multiworld detection reliable. Although this will change which waypoint sub-world is "auto".