How to install Mage.PRO extensions without Composer (not recommended way)

We just paid and downloaded, «Price Format» Magento 2 extension. Now I have its files but how to install it ? just drag and drop to root ?

The recommended method to install a Magento 2 extension is by Composer.
Here are Composer instructions for my extensions: https://mage2.pro/c/meta/first-steps

how can I install without composer ? I just extract the zip of your extension and put it into htdocs/magento2/app/code/Dfe/CurrencyFormat then ran “n98-magerun2.phar setup:upgrade” then it said it was installed but when I log into admin panel and navigate to system->configuration , it returns an error
"Invalid XML in file /Applications/mamp2/apache2/htdocs/magento2/app/code/Dfe/CurrencyFormat/etc/adminhtml/system.xml:
Element ‘field’, attribute ‘dfItemType’: The attribute ‘dfItemType’ is not allowed.
Line: 20"

what did I done wrong ?

If you do not use Composer then you should manually do all the instructions in the all the composer.json files.

The error you got is because you did not properly installed Mage2.PRO core package.
Look at the line http://code.dmitry-fedyuk.com/m2/all/blob/8d6d40/composer.json#L17

"extra": {"map": [["*", "Df"]]}

If you do not use Composer then you should reproduce such filesystem operations manually.

How the filesystem should looks like:

ok file structure is not as yours , I think I have done something wrong , honestly your installation steps are not clear to me for composer installation , I have downloaded zip file so now what should I do where to paste it ?

Step 1

"extra": {"map": [["*", "Df"]]}

This Composer instruction means that you should place the Mage2.PRO core package into the Df folder (see the picture above).

Step 2

http://code.dmitry-fedyuk.com/m2e/currency-format/blob/a30e7fb/composer.json#L14

"extra": {"map": [["*", "Dfe/CurrencyFormat"]]}

This Composer instruction means that you should place the Mage2.PRO «Price Format» package into the Dfe/CurrencyFormat folder (see the picture above).

I can also install it by myself if you give me SSH acсess to the server.

at the moment there is an issue with dx3 servers I will send ssh access tomorrow

I have sent ssh access did you check ?