I have been a user of the ToS platform (live and simulated) for many years. I trade emini S&P 500 options (Symbol ES) credit spreads. That said, your question begs a few more questions, e.g.;
what symbol did you trade
stock, etf, futures
why did you decide on that particular symbol
fundamental and/or technical analysis
what expiration date
how did you you choose expiration date and strike(s) of the call you sold
did you use ToS' Options Hacker (under the scan tab)feature to identify the call you sold
did you use ToS' Analyze tab to look at risk analysis and probabilities
what criteria did you use in your scan(e.g. Probability, Delta, days to exp, Vol)
did you have a stop loss number in mind and did you place that order along with your sell order
do you have a written trading plan and, along with that,
do you have a written trading strategy
did you follow your plan and strategy
When entering a trade i always use the foregoing questions before hitting the send order button. You need to have a plan and, as a part of that plan, a strategy and be able to stick to it.
I recommend that, if you haven't already, read the following books which are a part of my library and which I have found to be useful.
Options Pricing and Volatility (2nd Ed.)
Natenberg
The Complete Guide to Options Selling (3rd Ed.)
Cordier and Gross
Getting Started in Options (8th Ed.)
Thomsett
All About Options (3rd Ed.)
McCafferty
Trading Weekly Options
Rhoads
Options Spread Trading
Rhoads
Vertical Options Spreads
Conrick and Hanson
Options as a Strategic Investment (5th Ed.)
McMillan
The Bible of Options Strategies (2nd Ed.)
Cohen
Trading Psychology 2.0: From Best Practices to Best Processes
Steenbarger