Multi Domain

Problem: I cannot apply WordPress MU Domain Mapping plugin to link 2nd domain to my main domain wordpress install.

Questions:
1) Is it my fault, if so, please see below steps, or
2) Is my host correctly in saying the plugin doesn’t work because the host has shared server?

– Host is: one.com
– Plugin link: WordPress MU Domain Mapping

Domains:
1. https://www.kietygory.com (main)
2. https://www.scandinaviansolution.se (2nd domain)

According to brianshim, we need to first setup multisite and then domain mapping.

Multisite setup:
1. I created WP multisite on kietygory.com via this WP codex. (changed wp-config.php). In Wp-admin, this gave me “my sites” and “network settings. See picture – yellow box.
2. Then, I created a subdomain: https://www.kietygory.com/test1

Domain Mapping setup:
3. I installed MU Domain Mapping plugin in kietygory.com (followed plugin instructions). This gave me Domain Mapping and Setup. See picture – blue box.
4. I went into host of scandinaviansolution.se into DNS admin. Made it redirect to kietygory.com. The Type redirect is Web alias. The Type is not A record since the host A record is One.com Network.
5. Problem – according to the instruction video, I should get domain list in “sites”. I don’t, what I do have is subdomain list. See picture.

Possible solutions (I want to check with you first before I try the problems):
1. Restart installation, skip multisite and go directly to domain mapping?
2. Restart WP install and use the truncated plugin from Otto instead of WPMU?
3. No solution – my host was right, since they are a shared server, cannot do this?