You can add totally custom HTML and CSS to create a legend or other custom control that can be placed easily on your map.
https://wpmaps-docs.mapster.me/pro-features/pro-maps/custom-html-control
Here is the HTML and CSS used in this example:
<style> .legend-container { width: 200px; height: 40px; margin: 10px; background: rgba(255,255,255,0.6); } .legend-container .colors, .legend-container .details { width: 100%; display: flex; } .legend-container .colors > div, .legend-container .details > div { width : 25%; height: 20px; text-align: center; } .legend1 { background : blue; } .legend2 { background : green; } .legend3 { background : red; } .legend4 { background : black; } </style> <div class="legend-container"> <div class="colors"> <div class="legend1"></div> <div class="legend2"></div> <div class="legend3"></div> <div class="legend4"></div> </div> <div class="details"> <div class="detail">0%</div> <div class="detail">25%</div> <div class="detail">50%</div> <div class="detail">100%</div> </div> </div>