There are many types of leads, some leaning more towards the technical side and some focusing more on "people management". Regardless you will be judged by your abilities to lead and grow a team. Hence, apart from the usual stuff (i.e. knowing your domain very well) you should demonstrate communication and leadership skills in both technical as well as team-related topics.

Some examples:

• Communication / Clarity: Being able to ask clear questions and providing context. Getting to the point. Ideally, a lead should be able to clearly demonstrate a vision, a plan, and how to execute it. Ask for feedback and give feedback during the interview process!
• Mentoring and Guidance: Prepare examples of how you successfully coached Junior/Mid/Senior peers, developed career frameworks, provided guidance, onboarding, etc.
• Mediation: You should have an understanding of conflict management and experience resolving conflicts and different points of view. Definitely show a good understanding of various position's goals and points of view (PM, Tech/Team lead, BE, FE, UX/UI, etc.).
• Technical Stewardship: You should be able to have a clear understanding of common strategies to balance technical debt and feature development. This naturally includes deep knowledge about CI/CD, testing strategies, documentation, maintainability, code smells, etc. Additionally, you should know current trends and have educated opinions on short, mid, and long-term frontend stacks. Please don't be dogmatic.
• Motivation: Crediting the team, staying humble, leading by action, not blaming, etc. Show that you are not only a team player but someone the company can rely on to keep morale up during stressful times.
• Hiring: You should have a basic understanding of the whole recruitment process and a good understanding of interviewing practices.
• Ownership: Demonstrate integrity and accountability
• So many more things we could talk about but these are common interview topics for lead positions.

As you are asking this question I assume you don't have previous experience working as a lead so some of these topics might be new to you. If you think about previous projects I'm sure you can find some examples for these topics ("On project X I was responsible for onboarding and mentoring x junior / mid-level engineers", etc.).