"Critical" does not mean "negative".

The critical summary should include: (i) a brief description of what the webinar is about and (ii) your opinion on it, including what was persuasive, what was not and what could have been improved. If you don't understand (a part of) technical analysis, it is fine. Generally, in a critical summary it is important to answer the following points: 

What is the motivation for the research? Why should we care about this research (why is it important)?  

What is the identification strategy that helps to answer research questions (e.g. experiment design; change in legislation; cross-country differences; an exogenous shock)? 

What is a key part of the research that allows authors to claim what they claim? 

What are the main findings? Are these surprising or rather expected? What implications do authors claim these findings have? How is this research new? 

The most important is that you include your personal view on the topic, the potential extension of the research idea or discussion about the strengths and weaknesses of the presented research.  If you can compare the presented research to other similar research that you find - do it.

Formal requirements

Use this template for writing your essay. You can read an example of essay.

The critical summary should be about 700 words (two pages). No copy-paste and no plagiarism is acceptable, be sure you do proper referencing! If you are not sure how to reference and/or paraphrase, read this material (link). Write clear, simple and short sentences. Avoid complicated text structures with no meaning. You can use Grammarly software to correct typos and simple grammar mistakes. Submit text that makes a good impression of your work.