Hi @sarahhoelscher
Here's the [https://download.lenovo.com/consumer/mobiles_pub/yogac930-13ikb_yogac930-13ikbglass_hmm_201902.pdf|hardware maintenance manual] for the laptop.
Go to p.44 to view the procedure to remove/replace the pen holder.
On p.62 Item #5 you'll find the part number for the pen holder. Search online for ''Lenovo 5M20S7305'' to find suppliers that suit you best.