The state labor department has shut down its tool for certifying people for extra $300 weekly unemployment payments until it is sure the system can meet demand, officials said Wednesday. The shutdown will not affect people’s ability to collect money they are entitled to through the Lost Wages Assistance program, officials say. The Colorado Department of Labor and Employment launched the certification function, accessed through its “virtual agent” automated customer service system, on Friday, deputy executive director Cher Haavind said in an email Wednesday. The certification tool worked well over the weekend, leading the department to contact more than 220,000 people on the state’s unemployment rolls Monday to encourage them to call in or log on and certify their eligibility, Haavind said in a email. By that evening, the system began struggling with the demand and preventing some users for completing the process.