Making Land Transport from existing unit(Solved)

✋ Hello! I'm trying to add an ability of transportation units for Seraphim T1 Medium Tank (Thaam).
I have already changed necessary "Command Caps" in unit's blueprint - transport = true - I want it only manual transporting without "Ferry" function, and added "Transport Class" in this blueprint, also I have created a bone for attaching other units and carrying it like in "Vish", "Vishala" and other transports - I tested it and it works (wrote some commands in script file to create already attached unit) and my Thaam can unload inner unit, but the Question is - How to make Thaam attach units? There is no problem with carrying and unloading as I wrote above.
When I hovering cursor (Thaam is already selected) to wishful unit (I tried with Mech Marine and Selen) the icon of uploading appears, but when I'm clicking on it nothing happens and in reverse when I'm doing this all from selected Mech Marine. Unit is not loading.

What I need to do to make this function works?
I've checked all the scripts from SC transports and even from BrewLan mod (there is an incredible cybran t4 land transport) and F.B.P. with its infantry amphibious boat and still can not understand what to write or add.

Note: I'm a newbie in modding and started 3 days ago.

UPD: Uploaded archive file with modded blueprint, script and model in highpoly.
Thaam.rar

i have no clue how transports works,

but when i look at the attachcode, its looking for attachpoint name like:

Attachpoint_Lrg
Attachpoint_Med
Attachpoint

but your bones are called:
AttachPoint
AttachPoint_Med

those names are case sensitive!!!
make the "p" in point lower case please.

Uveso, names of bones are identical in script and model, I haven't found any mistakes, but I changed both names from AttachPoint to Attachpoint and nothing has changed.

please just rename the bones in your model
i have tested it and its working.

Starrk_Thaam.zip

i also fixed the lod_0 and lod_1 AlbedoName, SpecularName and NormalsName
in case you want to use this as stand alone unit in a mod.

[edit]
the bones need to match the names in the SupCom code like here:
https://github.com/FAForever/fa/blob/deploy/fafdevelop/lua/ScenarioFramework.lua#L1536

Man, big thanks to you, I finally got it) And thanks for this lua - it will really help me in further work

you are welcome