1. You need go to Admin -> Extensions -> Templates (Joomla 3), then click the "Options" button in the toolbar.
For Joomla 4 - Joomla 5, go to System -> Templates -> Site Templates), then click the "Options" button in the toolbar.
2. There click "Enable" for "Preview Module Positions"
3. Go to your site as example: ordasoft.com, and add to url parameter "tp=1".
So url will look like: ordasoft.com?tp=1
and check your Joomla Modules positions preview
Any Joomla module positions, for your module, you may select In Joomla Module Manager.
1. Please go to Admin -> Extensions -> Modules (Joomla 3)
Please go to Admin -> System -> Manage -> Site Modules(Joomla 4 - Joomla 5)
2. Select your Joomla module.
3. Set Joomla module positions for Joomla module.
More useful links:
Joomla load module to articles: loadmodule, loadposition, loadmoduleid.
How to display module positions in joomla templates.