Themeorest US Backup Withholding Tax (withheld)- $243.48.How to received my payment.
You can’t claim withholding tax back.
Depending where you are located then you may be able to minimise it in the future.
Did you complete the relevant tax docs? https://help.author.envato.com/hc/en-us/articles/360000471263-Tax-Information-Form-W-9-Requirements-for-US-Authors
For reducing US backup withholding tax (24%) you should to submit your TAX information form. If you submit the form with your TAX information then only tax will be taken for US sale and TAX percentage depends on your country.
US Tax Treaties:
Otherwise you have to give US backup withholding tax (24%) for all of your sale.
But for getting that tax facility you have to provide TAX information through settings=>tax information. When you complete your tax information, you must also provide Tax Identity Number, otherwise, Envato are required to deduct royalty withholding tax of 30% on your sales to US customers.
Tax Information & Form W-8 Requirements for non US Authors:
The country Singapore is not there in the list
If any country is not there in the US Tax Treaties list then that country have no tax treaty with US. In the case of an author in a country with no tax treaty, then RWHT is 30% if the sale is to a US buyer.