Describe the problem related to the feature request

有时候需要测试插件处理多行内容的效果，然而沙盒只能发单行，不能换行

Describe the solution you'd like

输入框改用textarea，支持shift+enter换行，并增加发送按钮以支持触屏用户

Describe alternatives you've considered

No response

Additional context

No response