If I have employee business expenses as a physician on line 10 of form 2106. Why don't they show up on line 12 of Schedule 1, Form 1040 .

Employee business expenses are not deductible on a federal tax return due to the changes in the tax code that are in effect for tax years 2018 thru 2025

As a physician, you are not eligible to deduct unrimbursed business expenses.  According to the IRS:

Use Form 2106 if you were an Armed Forces reservist, a qualified performing artist, a fee-basis state or local government official, or an employee with impairment-related work expenses. Employees who do not fit into one of the listed categories may not use the Form 2106 due to the suspension of miscellaneous itemized deductions subject to the 2% floor under section 67(a). Section 67(g) suspends miscellaneous itemized deductions for tax years beginning after December 31, 2017, and before January 1, 2026.