Use the Select block to add dropdown menus that let users choose one or more options. This block is essential for collecting input via a <select> element and supports both single-select and multi-select variations.
To add a Select block, create a new form and open the Block Inserter tool. Use the search bar to find the Select block and click on its icon to insert it into the editor.
You can also choose the Select block from the “Block Inserter” (+) pop-up window when you click on the (+) sign.
Detailed instructions on adding blocks
Block Settings
The Select block supports Color, Spacing, Border, and Dimensions settings.
Official documentation for these settings controls are available on WordPress.org: