I bought ryzen threadripper 3990x and liquid MSI coreliquid k360 but there not have a connector to TR4. Were can I buy them?
MSI website for your AIO CPU Cooler has a Youtube video on how to install it on a TR4 Motherboard: https://www.msi.com/Liquid-Cooling/MPG-CORELIQUID-K360
NOTE: You didn't mention what part you needed to connect to the TR4 motherboard but I would open a MSI Support ticket if you have any parts missing from your CPU Cooler.
I think Orloc is talking about the mounting bracket included in 3990x boxed retail.
There is no attachment to TR4 in the kit, and support writes that it should not be there
Now they write that the bracket is included in the AMD processor kit:
https://ru.msi.com/Liquid-Cooling/MPG-CORELIQUID-K360/Specification
Threadripper 3990X Retail box & contents
Ask the seller about the missing part/s.
I bought an OEM package
In the image by @goodplay it shows the Ryzen 9 3990x Mounting Bracket:
Now if you purchased the Ryzen 3990x and it didn't come in a official AMD Retail Box then you need to ask the vender or seller to try and get you that mounting bracket that comes inside a AMD Retail Box since they are the one in charge of your Warranty and not AMD.
AMD 3 year Warranty only covers Users that purchase a sealed AMD Retail Box processor. OEM Processors Warranties are coverered by the Retailer or vendor that sold you the OEM Processor.
OEM Processors are sold generally in a plastic Clamshell or Non-AMD box without any accessories which makes them cheaper than the Sealed AMD Retail Box that does come with all the extra accessories. But the AMD Warranty is voided.