I cannot enter additional Reservist expenses on Form 2106 Line 6 because that screen doesn't appear. Only expenses I can input is for travel. How do I get to Line 6?

Unfortunately, travel is the only thing that is deductible (if more than 100 miles) on your federal return.     However, you can go through the ''Other Expenses for Reservists'' section to enter your other expenses as these may be deductible on your state return.   On the screen that says ''Is your work part of one of these professions?''   Choose the last option (I wasn't in any of these situations) to enter all of your other (non-travel over 100 miles) expenses. 

If you are a member of a reserve component of the Armed Forces and you travel more than 100 miles away from home in connection with your performance of services as a member of the reserves, you can deduct your unreimbursed travel expenses on your tax return. Include all unreimbursed expenses from the time you leave home until the time you return home. 

All other W-2 job expenses have been suspended for tax years 2018-2025 for federal returns.  The new law suspended the deduction for job-related expenses or other miscellaneous itemized deductions that exceed 2 percent of adjusted gross income.  This includes unreimbursed employee expenses such as uniforms, union dues, and the deduction for business-related meals, entertainment, and travel.  There is an exception for travel in the case of Armed Forces Reservists.   And also, some states still allow these.  

Publication 3 (2020), Armed Forces' Tax Guide