item earnings

I have some items with 19 $ and every sell I earn only 5.37 $ of the 19$ >>
why this happen ?

Have you submitted tax information? Do so here:

Authors outside of the US will have withholding tax on their sales. If your country has a tax treaty with the US, you can reduce or eliminate this withholding tax by submitting your tax info. You’ll still have tax withheld on US-based sales, but with a tax treaty you’ll be able to get this money back through your government when paying your taxes.

If you don’t submit tax info then Envato will assume you’re a US author and will withhold tax on all of your sales.