Bootstrap 5 [↗] no longer uses the btn-block class to create full-width buttons.

To create a full-width button you will need to wrap the button in a tag that has a grid class i.e.: d-grid (grid display class)

📋 Copy🚫 Word Wrap
01: <div class="d-grid">
02:   <button type="submit" class="btn">Submit</button>
03: </div>

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