In addition to @Reza's reply. In Compose, you can just pass ByteArray in model:

import kotlin.io.encoding.Base64
import kotlin.io.encoding.ExperimentalEncodingApi
/*private const val*/ BASE64_SUBSTRING = "base64,"


@OptIn(ExperimentalEncodingApi::class)
val base64ImageByteArray = Base64.decode(base64ImageString.substringAfter(BASE64_SUBSTRING))

AsyncImage(
    model = base64ImageByteArray,
    contentDescription = null,
    placeholder = ColorPainter(MaterialTheme.colorScheme.surfaceContainer),
    error = ColorPainter(MaterialTheme.colorScheme.surfaceDim),
    contentScale = ContentScale.Crop,
)