It's true, the company you're interviewing will use the salary you currently earn to determine the salary they will offer you. Even if you don't tell them how much that is, they know. The problem with that is, you're current company isn't paying you the full value of the skills that you provide. So, how do you change this? Resume Load, that's how.
When you prepare your resume, don't assume your "title" tells the story of what you actually do. In the technology field there are hundreds of positions labeled "IT Specialist", maybe five of those actually do the same thing; maybe. It's up to you to tell the full story of the valuable skills you offer. Let the company you're interviewing with read your resume and think "geeze this person is under paid". This is the conversation you want to have, it will actually lessen the salary and benefits negotiations.
An easy way to Resume Load:
Take a blank piece of paper and write out, in bullets, everything you did at work in the last 2 weeks.
Take another blank piece of paper and write out the skill set your new company is looking for.
Take both sheets of paper and match up your actual job activities with the skills the new company or career promotion you're applying for.
Take all the other job activities and label them, these are the bonus skills which will start the "under paid" conversation.
Don't forget to list out the courses you've taken, career networks you've joined and additional projects you completed during COVID (yeah, I know you did a lot).
This isn't something you can do in a matter of minutes, but its worth every hour you spend on it. It could possibly be the 6-figures with remote work and additional PTO kind of difference.
NOTE: if you need additional help, be sure to join the Career Success Lifestyle FB group.