Convert Figma CSS Properties to TailwindCSS utilities. This is only partially functional, feel free to take this code and use it to build your own plugin.

code.ts

/** Converts Figma CSS Properties to TailwindCSS utilities.
 * This plugin is unfinished, feel free to take this code and extend it to build your own plugin!
 * @author James Ives - https://jamesiv.es
 * 
 */

const convertComponentToHex = (c: number) => {
  const hex = c.toString(16);
  return hex.length == 1 ? "0" + hex : hex;
};

const rgbToHex = (r: number, g: number, b: number) =>
  `#${convertComponentToHex(r)}${convertComponentToHex(
    g
  )}${convertComponentToHex(b)}`;

const getRGBValues = ({ r, g, b }) =>
  [r, g, b].map((channel) => Math.round(channel * 255));

figma.showUI(__html__);
figma.ui.onmessage = (msg, callback) => {
  if (msg.type === "convert-element") {
    if (
      figma.currentPage.selection.length &&
      figma.currentPage.selection.length === 1
    ) {
      const selection = figma.currentPage.selection[0];

      if (selection.type === "RECTANGLE") {
        const height = selection.height;
        const width = selection.width;
        const radius = selection.cornerRadius;
        const opacity = selection.opacity;
        const fill = selection.fills[0];

        const sheet = {
          height: `h-[${height}px]`,
          width: `w-[${width}px]`,
          radius: `rounded-[${String(radius)}px]`,
          opacity: `opacity-[${opacity}]`,
          background: ``,
          effects: ``,
        };

        // Applies effects for things such as drop shadows.
        selection.effects.forEach((effect) => {
          if (effect.type === "DROP_SHADOW") {
            const [r, g, b] = getRGBValues(effect.color);
            sheet.effects += `shadow-[${effect.offset.x}px_${effect.offset.y}px_${effect.radius}px_${effect.spread}px_rgba(${r}, ${g}, ${b}, ${effect.color.a})]`;
          }
        });

        //
        if (fill.type === "SOLID") {
          const [r, g, b] = getRGBValues(fill.color);
          const hex = rgbToHex(r, g, b);

          sheet.background = `bg-[${hex}]`;
        }

        if (fill.type === "GRADIENT_LINEAR") {
          fill.gradientStops.forEach((stop, index, array) => {
            const [r, g, b] = getRGBValues(stop.color);
            const hex = rgbToHex(r, g, b);

            if (index === array.length - 1) {
              sheet.background += `to-[${hex}] `;
            } else if (index === 0) {
              sheet.background += `bg-gradient-to-b from-[${hex}] `;
            } else {
              sheet.background += `via-[${hex}] `;
            }
          });
        }

        // Alerts the converted properties to Figma.
        alert(`${[...Object.values(sheet)].join(" ")}`);
      } else {
        // If the user attempts to run the plugin on an unsupported selection type, inform them.
        alert("Selection type not supported");
      }
    } else {
      // If the user attempts to run the plugin on multiple nodes at once, inform them. 
      alert("Please select a single node");
    }
  }

  figma.closePlugin();
};

ui.html

<h2>Convert to TailwindCSS Classes</h2>
<button id="create">Convert</button>
<script>

document.getElementById('create').onclick = () => {
  parent.postMessage({ pluginMessage: { type: 'convert-element' } }, '*')
}

</script>