R leaflet display the polygon label by default - html

Question

I am new to the leaflet package.
I am trying to draw two types of polygons and let the user select them and see the borders. These polygons have labels and I want to display them by default. At the moment the labels are displayed only on mouse hover.
Basically what I want is to let the user search for the polygon label on the map.
Given below is my code.
shp <- readOGR(dsn = 'shapes'
,layer = 'SAB')
postcode <- readOGR(dsn = 'shapes'
,layer = 'Postcode')
CRS_WGS84 <- '+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0'
t_shp <- spTransform(shp, CRS(CRS_WGS84))
sab_shp <- raster::aggregate(t_shp, by='SMALL_AREA')
dat <- data.table(shp#data)
sabLabels <- sprintf('<strong>SAB: %s', t_shp$SMALL_AREA) %>% lapply(HTML)
postcode <- readOGR(dsn = 'shapes'
,layer = 'Postcode')
CRS_WGS84 <- '+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0'
t_shp2 <- spTransform(postcode, CRS(CRS_WGS84))
postcode_shp <- raster::aggregate(t_shp2, by='RoutingKey')
dat2 <- data.table(postcode#data)
postcodeLabels <- sprintf('<strong>SAB: %s', t_shp2$RoutingKey) %>% lapply(HTML)
leaflet() %>%
addTiles() %>% #using default does not allow html export to include the underlying
#OSM layer
addProviderTiles('OpenStreetMap.Mapnik') %>%
addPolygons( data = t_shp
,stroke = T
,fillColor = 'grey'
,fillOpacity = 0.2
,color = 'blue'
,weight = 0.5
,label = sabLabels
,group = 'SABS'
,highlightOptions = highlightOptions(color = "blue", weight = 7,
bringToFront = TRUE)
#,labelOptions = labelOptions(noHide = TRUE, textOnly = TRUE, opacity = 0.5 , textsize='15px')
) %>%
addPolygons( data = t_shp2
,stroke = T
,fillOpacity = 0
,color = 'black'
,weight = 1.5
,label = postcodeLabels
,group = 'PostCodes'
) %>%
addLayersControl(
overlayGroups = c(
'SABS'
,'PostCodes'
)
,options = layersControlOptions((collapsed = F))
)