Over here are two examples of the plugin
There are two config files, but mainly you just need to use one - models.cfg (sourcemod/configs/models/models.cfg)
Every model that you add, can only be once placed in one map. If you want to place two same models in one map, then you need to create two same models with different name.
"Big banner 2"
Install!props - requires d flag(BAN)
It will open up menu, which will allow you to add models, that you have added in models.cfg.
You can move the block with E (When move models is turned on)
You can rotate block by 10° with R (When your holding the block)
You can push/pull block with Mouse 1, Mouse 2 (When your holding the block)
btw, after placing not solid block in the map, it will become non solid after round restart.
Download files & extract them
Add models in sourcemod/configs/models/models.cfg. If your adding custom models, download sm downloader, that will allow you to download & precache files.