Trail Blazer 05 won't start - ignition switch?

I’m a recent widow and my husband’s truck (Trail Plazer 05 EXT w/81K miles) won’t start after putting key in ignition and turning. Battery is fine, fuel fine. When I turn key in ignition to start, the icon with a lock on the engine lights up. The engine doesn’t engage, nor can I move it out of park. I’m literally stuck in park. Others thought starter, or solenoid; but now thinking ignition.

History: clean truck w/no issues until after rear rotors recently changed. ABS icon lite up once and stopped; next day key ignition didn’t start truck promptly (as it always had in the past), so I retried and it started fine. Then same trip, the truck lost all power and I glided to side of road. I was able to put it into park (though it had to be wiggled), remove key and restart the truck. I then brought to local garage and they tested on computer for disagnosis. They couldn’t reproduced problem, and drove it six times during the day with no issues. I drove it home that evening and to work the next day with no issues as well. After full day of work, I went to start and - no go, battery okay, dash lights engage, lock on engine still lit. I can’t engage the automatic shift out of park into neutral for towing either

Have other Trailblazers had this issue? Any ideas of what this might be? My budget is limited being newly widowed. I can’t afford to keep going to different garages and as I love the car talk radio show, I thought I’d ask the group for help before taking to the next garage. Many thanks and I truly appreciate it.

The lock icon means your car thinks someone is trying to steal it. Your owners manual should tell you how to reset it.

If you have the fob you can double click unlock before trying to start it and see if that at least gets you going.

What is a FOB? Sorry I don’t understand, this is all new to me.

The remote unlock thingy.

Now you are taking my language LOL. The remote keyless entry thingy. That’s at home now and will try tomorrow.

Some thought was that these key thingys get uncoded at times and to take the original key to dealer for recoding; but I had spare made w/o the plastic thingy and still ‘no’ go. So that idea got ruled out.

The transmitter might be bad? However, the malfunction wasn’t out of the blue. Had issues first with replacing of rear brake pad/roters so when ABS lights blinked and growned I was concern. Next day had issue engaging the engine; but on second key twist - got started, only to completely fail while driving and had to pull over. Removed key and start again, and was able to get to garage. Garage couldn’t find any issue on computer and then drove 6x times no issue. I had no issues the following am. rested it to the end of work day, and then ‘no go’ Can’t engage.

Don’t know if rotor work disengaged something, or just not related at all. Or if electrical issue, solenoid, stuck in shift gear, starter? Book suggested to to check fuses if it is the Passlock issue. Have no idea what to look for in a fuses other than where it is. Ideas?