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3. Allowance for Doubtful Accounts (Tables)
12 Months Ended
Dec. 31, 2020
Allowance for Credit Loss [Abstract]  
Schedule of allowance for doubtful accounts
    Years Ended December 31,  
    2020     2019  
Balance, beginning of year   $ 50     $ 50  
Provision for doubtful accounts            
Uncollectible accounts written off            
Balance, end of year   $ 50     $ 50