How to store values into a dataframe from a List using Scala for handling nested JSON data

Question

I have the below code, where I am pulling data from an API and storing it into a JSON file. Further I will be loading into an oracle table. Also, the data value of the ID column is the column name under VelocityEntries. I am able to print the data in completedEntries.values but I need help to put it into one df and add with the emedded_df

With the below code I am able to print the data in completedEntries.values but I need help to put it into one df and add with the emedded_df

val inputStream = scala.io.Source.fromInputStream(connection.getInputStream).mkString
val fileWriter1 = new FileWriter(new File(filename))
fileWriter1.write(inputStream.mkString)
fileWriter1.close()
val json_df = spark.read.option("multiLine", true).json(filename)
val embedded_df = json_df.select(explode(col("sprints")) as "x").select(("x.*"))
val list_df = json_df.select("velocityStatEntries.*").columns.toList
for( i <- list_df)
{
  completed_df = json_df.select(s"velocityStatEntries.$i.completed.value")
  completed_df.show()
}