Learning running script should be based on regular script, otherwise it will be soft and charming, or it will use too much brute force. In short, I can't find the rhythm of lifting pressure when writing. You can't write a good running script in this situation.

If you want to practice hard pen, buy a calligraphy pen, and then buy a stack of white paper, a copy of Zhao Mengfu's Tao Te Ching or Ling Fei Ching, and copy them carefully one by one. After you've practiced for a year, it's estimated that you should have no problem with the hard-pen handwriting.

Writing a running script without learning regular script is as absurd as running away, let alone writing well. Take your time, calligraphy is not fast.