Read and write spreadsheets with ruby using the spreadsheet gem

spreadsheet-examples.rb

# Read and write spreadsheets with ruby using the spreadsheet gem
# Full Docs: http://spreadsheet.rubyforge.org/GUIDE_txt.html

require 'spreadsheet'

# Open source spreadsheet
workbook = Spreadsheet.open 'source.xls'

# READ

# Specify a single worksheet by index
sheet1 = workbook.worksheet 0
sheet1.each do |row|
  puts "#{row[0]} - #{row[1]} - #{row[2]}"
end

# Specify a single worksheet by name
sheet2 = workbook.worksheet 'Sheet2'
sheet2.each do |row|
  puts "#{row[0]} - #{row[1]} - #{row[2]}"
end

# Loop over each worksheet
workbook.worksheets.each do |sheet|
  sheet.each do |row|
    puts "#{sheet.name} --> #{row[0]} - #{row[1]} - #{row[2]}"
  end
end

# WRITE

# Modify each worksheet (in memory)
workbook.worksheets.each do |sheet|
  sheet.each do |row|
    row[0] = 'foo'
    row[1] = 'bar'
  end
end

# Write (changes) to destination spreadsheet
workbook.write 'destination.xls'

/Ruby25-x64/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require': cannot load such file -- spreadsheet (LoadError)

this error is passing what is the solution for this?