Remote contol volumn won't work

Set-up (Programming) procedure is too much to type in here, and is not practical and it will differ brand-to-brand remote controls. If you wish to get more; check the sites linked here. It has set-up code list & set-up procedure to many popular brand remote controls. One among it has general set-up codes to check with TVs and other devices are given, in the order of the 'device's brand name list' in alphabetical order. Pull up older posts. Search the sites by type in the brand name to your device in its search box at the top right part of the display window. It will help you to find the document easily.
http://remotesearch.blogspot.com/
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/
http://electrohelponline.blogspot.com/
Search the site by type in the brand name of your device, in the "Search box at the top right of the Home page display" to see the set-up codes to your device, with different brand remote controls.

If you wish to get more details; check the sites linked here. It has set-up code list & set-up procedure to many popular brand remote controls. Common set-up codes to check with TVs and other devices are given, in the order of the "device's brand name list" in alphabetical order. Pull up older posts.
http://electro-medical.blogspot.com/

RCR450 have no setup codes to Apex TV. There is no RCA remote control models have set up codes for Apex brand.

I couldn't find any codes for Zenith in my code book, so I am wondering if it is made by another VCR maker and users that code?

Go to www.apex.com and query for the manual to the controller

lost my book need the code for an apex tv

Here is the PDF Owner's Manual:
http://www.apexdigitalinc.com/manual/AT3208S.pdf

i lost my code book for my ge remote control

all in one

I’m happy to assist further over the phone at https://www.6ya.com/expert/james_1cb31da1bc8c6102

What is the model number of the Apex TV you are using this remote for?
The CK5G-C1 remote was supplied only with model AT3208S TV. It will require no code when used with that model. If trying to use it with any other model TV, you can try the other Apex TV codes found in the AT3208s user's manual that can be found in .pdf format at : http://www.apexdigitalinc.com/manual/AT3208S.pdf
Let me know if this helps, or I can be of further help.
In any case, good luck!