Hi @kngsky
Yes the battery used in a 15m-bp1xx is a battery model # LK03XL
The ''HP part number'' for the battery, according to the [http://h10032.www1.hp.com/ctg/Manual/c05527167.pdf|maintenance and service guide], taken from this support webpage for a [https://support.hp.com/au-en/product/hp-envy-15m-bp100-x360-convertible-pc/16851048/manuals|HP ENVY 15m-bp100 x360] laptop, is ''916814-855''
To verify this either use the guide above to open the laptop to find the battery model number printed on the battery or search online using the [https://www.amazon.com.au/Battery-HSTNN-UB7I-TPN-W127-TPN-W128-916814-855/dp/B07FBFZMH1|HP part number] (supplier example only) to find suppliers that have the battery. If you look at the images of the battery on the supplier's webpage, you will see that the battery ''model number'' shown on the battery is LK03XL