If I have a capital investment that went sour (company went bankrupt). How I deduct the loss? Didn't get a 1099. I cant find place to enter the loss without a 1099.

You can enter it as an investment sale in the Wages and Income section of TurboTax, then Investments Sales, then Stocks, cryptocurrency, Mutual Funds, Bonds, etc... Skip the section where it asks if you want to upload your tax documents. Choose Other as the type of investment you want to enter. You'll come to a screen where you can enter in your sales proceeds and cost basis, enter $0 for the sale amount and what you invested as the cost:

The loss will be a capital loss. Net capital losses are only deductible up to $3,000 yearly , with any unused loss being carried over to the next year.