Recently, many banks have replaced leaderless groups with new forms such as debate contests, requiring candidates to be flexible.
If you feel that you are afraid to speak at ordinary times, or are easily nervous, you can buy some interview videos online to learn and introduce yourself to the mirror.
Find some students who are preparing for the bank exam to practice leaderless group and debate, and practice expression, form and tone.
If you are extroverted enough and have a lot of ideas in the process without a leading group, I suggest that you seize the leadership and organize everyone to discuss it together, which will add a lot of points.