DO NOT USE THIS MOD for general connected textures! Please use Continuity for this instead, as it yields much better performance. Only use this mod if it has features you need that Continuity does not have.
ConnectedTexturesMod for Fabric tries to maintain feature parity with the original ConnectedTexturesMod so that CTM/Chisel format resource packs can work on both platforms without any changes. CTMF also adds some new features and fixes some bugs from the original. It is a client-side only mod that requires the Fabric API and utilizes the Fabric Rendering API for efficiency and compatibility, but this means that it is incompatible with Sodium (unless Indium is used) and Optifine.
CTM/CTMF allows resource packs to create dynamic models by adding custom JSON to model or texture metadata files. CTM/CTMF by itself does not add connected textures. A separate resource pack is needed. CTM/CTMF also has a public facing API that allows other mods to add their own texture types, which can then be used through texture metadata.
Continuity is another Fabric mod that enables connecting textures through the use of a resource pack. Continuity allows resource packs to use Optifine/MCPatcher format, while CTMF allows resource packs to use CTM/Chisel format. The formats are different and some features that are available in one are not available in the other. There is also no tool to convert between the formats.
TL;DR: CTMF does not have support for Optifine format resource packs. Use Continuity for that instead.
The term "CTM" is ambiguous. In Optifine/MCPatcher format, which predates the ConnectedTexturesMod by a few years, "CTM" means "Connected Texture Map/Mapping". All mentions of "CTM" on this page and in any pages related to this project mean "ConnectedTexturesMod", unless otherwise specified. Depending on which meaning of "CTM" is implied, both CTMF and Continuity could be "CTM for Fabric", but as explained above, the mods serve different purposes.
For information on CTM/Chisel format, mod information, or porting information, visit CTM and CTMF's wikis.