TypeError: Cannot read properties of undefined (reading 'Layer')

TypeError: Cannot read properties of undefined (reading 'Layer')
    at https://unpkg.com/leaflet-truesize@3.1.0/dist/Leaflet.TrueSize.umd.js:3109:17
    at https://unpkg.com/leaflet-truesize@3.1.0/dist/Leaflet.TrueSize.umd.js:4:28
    at https://unpkg.com/leaflet-truesize@3.1.0/dist/Leaflet.TrueSize.umd.js:5:2