You were given good advice by Exopoulterer.
I would not use the VetRx as it doesn't really help with respiratory infections. It has a strong smell and this may be overwhelming to the chicken if it's on their face.
One who is laying but yesterday started sneezing and sounding congrsted and I noticed today her tongue looks whiter than normal. It doesn’t look like canker. No hunks or anything. Doesn’t smell.
It is hard to say what the white stuff is on her tongue without seeing a picture.
What does her congestion sound like? Is it raspy on every breath, does she look labored when breathing?
The Tylosin I've used is Doxy-Tyl which is 40g Tylosin and 10g Doxycyline. The measurement is 1 teaspoon per 1 gallon of water for 5-7 consecutive days with this being the only water source. It is used to treat upper and lower respiratory infections and mycoplasma. Tylosin without Doxy is good also so don't feel like you need to purchase anything else.
If you don't want to treat with water - as you would be treating the whole flock but everyone is exposed anyway, to treat only her, then you can try the Doxycycline tablets. Treatment is 1/2 pill to 1 whole pill per day depending on the weight of the bird for 5-7 days. With a respiratory infection, there is usually consistent and persistent coughing and sneezing with general malaise.
Unless they present with obvious respiratory symptoms, I would refrain from treating with too many antibiotics as this could lower their natural resistance. I understand you want to treat symptoms early if you do think they have a virus.
Sometimes if their environment is dusty depending on the substrate, this could cause sneezing or it could be something else in the environment, such as if you live near large farming operations where field work could be creating higher dust in the environment.
I didn't see any bubbles in the left eye in the video but it does look like it might be a little swollen; almost like there may be a bite or minor injury near the corner of her eye on the lower lid? It could have been the lighting in the video, it was hard to tell. If it looks to you like a bug bite or minor scratch injury, you can apply plain triple antibiotic (without pain relief) or plain neosporin to the eye.
Probiotics and electrolytes in the water after completing a round of meds to help restore the flora in their gut.
I'm new at this chicken thing too and still learning myself so I'm going to ask for a sanity check from
@coach723 to validate my response and solicit additional input.